[sanitizer] Enable threads for libc++ build used by the symbolizer

Disabling threads makes <atomic> unusable, but this is needed by LLVM
libraries that are dependencies of the symbolizer.

Differential Revision: https://reviews.llvm.org/D45424

llvm-svn: 329672

compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh

@@ -98,12 +98,10 @@ if [[ ! -d ${LIBCXX_BUILD} ]]; then
     -DLIBCXXABI_ENABLE_ASSERTIONS=OFF \
     -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF \
     -DLIBCXXABI_ENABLE_SHARED=OFF \
-    -DLIBCXXABI_ENABLE_THREADS=OFF \
     -DLIBCXX_ENABLE_ASSERTIONS=OFF \
     -DLIBCXX_ENABLE_EXCEPTIONS=OFF \
     -DLIBCXX_ENABLE_RTTI=OFF \
     -DLIBCXX_ENABLE_SHARED=OFF \
-    -DLIBCXX_ENABLE_THREADS=OFF \
   $LLVM_SRC
 fi
 cd ${LIBCXX_BUILD}

compiler-rt/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt

@@ -15,6 +15,10 @@ __divdi3 U
 __dso_handle U
 __errno_location U
 __interceptor_pread w
+__interceptor_pthread_cond_broadcast w
+__interceptor_pthread_cond_wait w
+__interceptor_pthread_mutex_lock w
+__interceptor_pthread_mutex_unlock w
 __interceptor_read w
 __interceptor_realpath w
 __moddi3 U