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/HOST_x86.mk b/core/clang/HOST_x86.mk
index 2803517..2e0865b 100644
--- a/core/clang/HOST_x86.mk
+++ b/core/clang/HOST_x86.mk
@@ -1 +1,2 @@
 $(clang_2nd_arch_prefix)HOST_LIBPROFILE_RT := $(LLVM_RTLIB_PATH)/libclang_rt.profile-i386.a
+$(clang_2nd_arch_prefix)HOST_LIBCRT_BUILTINS := $(LLVM_RTLIB_PATH)/libclang_rt.builtins-i386.a