Do not re-export _Unwind_XXX symbols.

Bug: 130267141

Test: All system shared libraries do not contain global _Unwind_XXX symbols.
Change-Id: I79673753bb8197041bfe8ffb016d9f5fdf4cada5
Merged-In: I79673753bb8197041bfe8ffb016d9f5fdf4cada5
(cherry picked from commit cf788674176513efca5773cea0701e636669a057)
diff --git a/cc/config/global.go b/cc/config/global.go
index 78f24f2..8fc9ff2 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -83,6 +83,7 @@
 		"-Wl,--warn-shared-textrel",
 		"-Wl,--fatal-warnings",
 		"-Wl,--no-undefined-version",
+		"-Wl,--exclude-libs,libgcc.a",
 	}
 
 	deviceGlobalLldflags = append(ClangFilterUnknownLldflags(deviceGlobalLdflags),