Fix lld detection in standalone compiler-rt.

Summary:
Right now all hwasan tests on Android are silently disabled because they
require "has_lld" and standalone compiler-rt can not (and AFAIK was
never able to) set it.

Reviewers: pcc, dyung

Subscribers: dberris, mgorny, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D69196

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@375472 91177308-0d34-0410-b5e6-96231b3b80d8

Author: eugenis

Diff for: CMakeLists.txt

@@ -497,7 +497,7 @@ else()
   if(EXISTS ${COMPILER_RT_LLD_PATH}/ AND LLVM_TOOL_LLD_BUILD)
     set(COMPILER_RT_HAS_LLD TRUE)
   else()
-    set(COMPILER_RT_HAS_LLD FALSE)
+    set(COMPILER_RT_HAS_LLD ${COMPILER_RT_HAS_FUSE_LD_LLD_FLAG})
   endif()
 endif()
 pythonize_bool(COMPILER_RT_HAS_LLD)

Diff for: cmake/config-ix.cmake

@@ -146,6 +146,7 @@ check_library_exists(stdc++ __cxa_throw "" COMPILER_RT_HAS_LIBSTDCXX)
 
 # Linker flags.
 check_linker_flag("-Wl,-z,text" COMPILER_RT_HAS_Z_TEXT)
+check_linker_flag("-fuse-ld=lld" COMPILER_RT_HAS_FUSE_LD_LLD_FLAG)
 
 if(ANDROID)
   check_linker_flag("-Wl,-z,global" COMPILER_RT_HAS_Z_GLOBAL)