Undo workaround of flag filtering.

* Now header-abi-dumper does not complain about -fno-sanitize=implicit-integer-sign-change

Bug: 119558057
Test: make checkbuild
Change-Id: I80be08dd5aa184498bdbb83b42b877dbec152165
diff --git a/cc/config/clang.go b/cc/config/clang.go
index 46d8528..ae13fa2 100644
--- a/cc/config/clang.go
+++ b/cc/config/clang.go
@@ -91,9 +91,7 @@
 	"-Wl,-m,aarch64_elf64_le_vec",
 })
 
-var ClangLibToolingUnknownCflags = sorted([]string{
-	"-fno-sanitize=implicit-integer-sign-change",
-})
+var ClangLibToolingUnknownCflags = sorted([]string{})
 
 func init() {
 	pctx.StaticVariable("ClangExtraCflags", strings.Join([]string{