Move libgcc to libcrt.builtins

libgcc is kept behind libcrt.builtins to provide unwinder symbols and
any other missing symbols.

Bug: 29275768
Bug: 119007754
Test: m checkbuild
Change-Id: Ifb16ed87afc3391f8830d771971315515f929235
Merged-In: Ifb16ed87afc3391f8830d771971315515f929235
(cherry picked from commit b9d89322791c84ad7a76513c6373a5ac5d0de026)
diff --git a/core/clang/TARGET_x86.mk b/core/clang/TARGET_x86.mk
index 1b9c78c..5e2d57e 100644
--- a/core/clang/TARGET_x86.mk
+++ b/core/clang/TARGET_x86.mk
@@ -3,6 +3,7 @@
 $(clang_2nd_arch_prefix)RS_COMPAT_TRIPLE := i686-linux-android
 
 $(clang_2nd_arch_prefix)TARGET_LIBPROFILE_RT := $(LLVM_RTLIB_PATH)/libclang_rt.profile-i686-android.a
+$(clang_2nd_arch_prefix)TARGET_LIBCRT_BUILTINS := $(LLVM_RTLIB_PATH)/libclang_rt.builtins-i686-android.a
 
 # Address sanitizer clang config
 $(clang_2nd_arch_prefix)ADDRESS_SANITIZER_LINKER := /system/bin/linker_asan