[CMake] Build shared version of ASan and UBSan for Fuchsia

[phosek]

Summary

Fuchsia is no longer treated as UNIX which means we need to explicitly
enable building of shared versions of ASan and UBSan.

[jakehehrlich]

LGTM

compiler-rt/lib/asan/CMakeLists.txt

add_compiler_rt_runtime(clang_rt.asan
               ${ASAN_DYNAMIC_WEAK_INTERCEPTION}
       CFLAGS ${ASAN_DYNAMIC_CFLAGS}
       LINK_FLAGS ${ASAN_DYNAMIC_LINK_FLAGS}
                 ${VERSION_SCRIPT_FLAG}
       LINK_LIBS ${ASAN_DYNAMIC_LIBS}
       DEFS ${ASAN_DYNAMIC_DEFINITIONS}
       PARENT_TARGET asan)
 
-    if (UNIX AND NOT ${arch} STREQUAL "i386")
+    if ((FUCHSIA OR UNIX) AND NOT ${arch} STREQUAL "i386")
       add_sanitizer_rt_symbols(clang_rt.asan_cxx
         ARCHS ${arch})
       add_dependencies(asan clang_rt.asan_cxx-${arch}-symbols)
       add_sanitizer_rt_symbols(clang_rt.asan
         ARCHS ${arch}
         EXTRA asan.syms.extra)
       add_dependencies(asan clang_rt.asan-${arch}-symbols)
     endif()

compiler-rt/lib/ubsan/CMakeLists.txt

if(COMPILER_RT_HAS_UBSAN)
 
     add_compiler_rt_runtime(clang_rt.ubsan_standalone_cxx
       STATIC
       ARCHS ${UBSAN_SUPPORTED_ARCH}
       OBJECT_LIBS RTUbsan_cxx
       CFLAGS ${UBSAN_CXXFLAGS}
       PARENT_TARGET ubsan)
 
-    if (UNIX)
+    if (FUCHSIA OR UNIX)
       add_compiler_rt_runtime(clang_rt.ubsan_standalone
         SHARED
         ARCHS ${UBSAN_SUPPORTED_ARCH}
         OBJECT_LIBS RTSanitizerCommon
               RTSanitizerCommonLibc
               RTSanitizerCommonCoverage
               RTSanitizerCommonSymbolizer
               RTUbsan

compiler-rt/lib/ubsan_minimal/CMakeLists.txt

add_compiler_rt_runtime(clang_rt.ubsan_minimal
     OS ${SANITIZER_COMMON_SUPPORTED_OS}
     ARCHS ${UBSAN_SUPPORTED_ARCH}
     OBJECT_LIBS RTUbsan_minimal
     CFLAGS ${UBSAN_CFLAGS}
     LINK_FLAGS ${UBSAN_LINK_FLAGS}
     LINK_LIBS ${UBSAN_DYNAMIC_LIBS}
     PARENT_TARGET ubsan-minimal)
 
-  if (UNIX AND NOT APPLE)
+  if ((FUCHSIA OR UNIX) AND NOT APPLE)
     set(ARCHS_FOR_SYMBOLS ${UBSAN_SUPPORTED_ARCH})
     list(REMOVE_ITEM ARCHS_FOR_SYMBOLS i386 i686)
     add_sanitizer_rt_symbols(clang_rt.ubsan_minimal
       ARCHS ${ARCHS_FOR_SYMBOLS}
       PARENT_TARGET ubsan-minimal
       EXTRA ubsan.syms.extra)
   endif()
 endif()