[CMake][Fuchsia] Use PIC for Fuchsia runtimes

[phosek]

Summary

Disabling PIC globally also disabled PIC for runtimes which was
undesirable, manually override it.

[leonardchan]

Should _LLVM_ENABLE_PIC ON also be added for the multilibs?

[phosek]

In D103919#2806198, @leonardchan wrote:

Should _LLVM_ENABLE_PIC ON also be added for the multilibs?

It should be propagated automatically.

clang/cmake/caches/Fuchsia-stage2.cmake

if(LINUX_${target}_SYSROOT)
     set(RUNTIMES_${target}_CMAKE_BUILD_TYPE RelWithDebInfo CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_C_FLAGS "--target=${target}" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_CXX_FLAGS "--target=${target}" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_ASM_FLAGS "--target=${target}" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_SYSROOT ${LINUX_${target}_SYSROOT} CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_SHARED_LINKER_FLAGS "-fuse-ld=lld" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_MODULE_LINKER_FLAGS "-fuse-ld=lld" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_EXE_LINKER_FLAGS "-fuse-ld=lld" CACHE STRING "")
+    set(RUNTIMES_${target}_CMAKE_POSITION_INDEPENDENT_CODE ON CACHE BOOL "")
     set(RUNTIMES_${target}_COMPILER_RT_USE_BUILTINS_LIBRARY ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_ENABLE_SHARED OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_INSTALL_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_ENABLE_STATIC_UNWINDER ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
-    set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS ON CACHE BOOL "")
+    set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
+    set(RUNTIMES_${target}_LLVM_ENABLE_PIC ON CACHE BOOL "")
     set(RUNTIMES_${target}_SANITIZER_CXX_ABI "libc++" CACHE STRING "")
     set(RUNTIMES_${target}_SANITIZER_CXX_ABI_INTREE ON CACHE BOOL "")
     set(RUNTIMES_${target}_LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
 
     # Use .build-id link.
     list(APPEND RUNTIME_BUILD_ID_LINK "${target}")
   endif()
 endforeach()
foreach(target x86_64-unknown-fuchsia;aarch64-unknown-fuchsia)
     set(RUNTIMES_${target}_CMAKE_BUILD_WITH_INSTALL_RPATH ON CACHE BOOL "")
     set(RUNTIMES_${target}_CMAKE_ASM_FLAGS ${FUCHSIA_${target}_COMPILER_FLAGS} CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_C_FLAGS ${FUCHSIA_${target}_COMPILER_FLAGS} CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_CXX_FLAGS ${FUCHSIA_${target}_COMPILER_FLAGS} CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_SHARED_LINKER_FLAGS ${FUCHSIA_${target}_LINKER_FLAGS} CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_MODULE_LINKER_FLAGS ${FUCHSIA_${target}_LINKER_FLAGS} CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_EXE_LINKER_FLAGS ${FUCHSIA_${target}_LINKER_FLAGS} CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_SYSROOT ${FUCHSIA_${target}_SYSROOT} CACHE PATH "")
+    set(RUNTIMES_${target}_CMAKE_POSITION_INDEPENDENT_CODE ON CACHE BOOL "")
     set(RUNTIMES_${target}_COMPILER_RT_USE_BUILTINS_LIBRARY ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_HIDE_SYMBOLS ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_INSTALL_STATIC_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_ENABLE_STATIC_UNWINDER ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_HERMETIC_STATIC_LIBRARY ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_INSTALL_STATIC_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_STATICALLY_LINK_UNWINDER_IN_SHARED_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_HERMETIC_STATIC_LIBRARY ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
-    set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS ON CACHE BOOL "")
+    set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
+    set(RUNTIMES_${target}_LLVM_ENABLE_PIC ON CACHE BOOL "")
     set(RUNTIMES_${target}_LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
 
     # Compat multilibs.
     set(RUNTIMES_${target}+compat_LLVM_BUILD_COMPILER_RT OFF CACHE BOOL "")
     set(RUNTIMES_${target}+compat_LIBCXXABI_ENABLE_EXCEPTIONS OFF CACHE BOOL "")
     set(RUNTIMES_${target}+compat_LIBCXX_ENABLE_EXCEPTIONS OFF CACHE BOOL "")
     set(RUNTIMES_${target}+compat_CMAKE_CXX_FLAGS "${FUCHSIA_${target}_COMPILER_FLAGS} -fc++-abi=itanium" CACHE STRING "")
 

clang/cmake/caches/Fuchsia.cmake

if(STAGE2_LINUX_${target}_SYSROOT)
     set(BUILTINS_${target}_CMAKE_SYSTEM_NAME Linux CACHE STRING "")
     set(BUILTINS_${target}_CMAKE_BUILD_TYPE Release CACHE STRING "")
     set(BUILTINS_${target}_CMAKE_SYSROOT ${STAGE2_LINUX_${target}_SYSROOT} CACHE STRING "")
 
     set(LLVM_RUNTIME_TARGETS "${target}" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_SYSTEM_NAME Linux CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_BUILD_TYPE Release CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_SYSROOT ${STAGE2_LINUX_${target}_SYSROOT} CACHE STRING "")
+    set(RUNTIMES_${target}_CMAKE_POSITION_INDEPENDENT_CODE ON CACHE BOOL "")
     set(RUNTIMES_${target}_COMPILER_RT_USE_BUILTINS_LIBRARY ON CACHE BOOL "")
-    set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_ENABLE_SHARED OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_INSTALL_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_ENABLE_STATIC_UNWINDER ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
+    set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
+    set(RUNTIMES_${target}_LLVM_ENABLE_PIC ON CACHE BOOL "")
     set(RUNTIMES_${target}_LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
     set(RUNTIMES_${target}_SANITIZER_CXX_ABI "libc++" CACHE STRING "")
     set(RUNTIMES_${target}_SANITIZER_CXX_ABI_INTREE ON CACHE BOOL "")
   endif()
 endif()
 
 if(UNIX)
   set(BOOTSTRAP_CMAKE_SHARED_LINKER_FLAGS "-ldl -lpthread" CACHE STRING "")