[cmake] Move LLVM_BUILD_STATIC check to an earlier point

[labath]

Summary

The motivation for this is to enable correct detection of dlopen() on Android.
Android does not provide a static version of libdl, so if we add the -static flag
after performing the check, it will succeed even though subsequent link steps
will fail. With this change we correctly detect the absence of libdl in a
LLVM_BUILD_STATIC build on Android.

The link itself still does not succeed because the code does not check the result
of this check properly, but I plan to fix that in a separate change.

[labath]

@beanz, could you give this a quick look?

[beanz]

LGTM.

CMakeLists.txt

if(NOT LLVM_PROFILE_FILE_PATTERN)
     if(NOT LLVM_PROFILE_DATA_DIR)
       file(TO_NATIVE_PATH "${LLVM_BINARY_DIR}/profiles/%${LLVM_PROFILE_MERGE_POOL_SIZE}m.profraw" LLVM_PROFILE_FILE_PATTERN)
     else()
       file(TO_NATIVE_PATH "${LLVM_PROFILE_DATA_DIR}/%${LLVM_PROFILE_MERGE_POOL_SIZE}m.profraw" LLVM_PROFILE_FILE_PATTERN)
     endif()
   endif()
 endif()
 
+if (LLVM_BUILD_STATIC)
+  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static")
+endif()
+
 # All options referred to from HandleLLVMOptions have to be specified
 # BEFORE this include, otherwise options will not be correctly set on
 # first cmake run
 include(config-ix)
 
 string(REPLACE "Native" ${LLVM_NATIVE_ARCH}
   LLVM_TARGETS_TO_BUILD "${LLVM_TARGETS_TO_BUILD}")
 list(REMOVE_DUPLICATES LLVM_TARGETS_TO_BUILD)

cmake/modules/HandleLLVMOptions.cmake

if( LLVM_BUILD_32_BITS )
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32")
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
     set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
     set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -m32")
   endif( LLVM_BUILD_32_BITS )
 endif( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
 
-if (LLVM_BUILD_STATIC)
-  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static")
-endif()
-
 if( XCODE )
   # For Xcode enable several build settings that correspond to
   # many warnings that are on by default in Clang but are
   # not enabled for historical reasons.  For versions of Xcode
   # that do not support these options they will simply
   # be ignored.
   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_RETURN_TYPE "YES")
   set(CMAKE_XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_NEWLINE "YES")