Export clang coverage flags

Configurate clang coverage flags in soong and export to makefile.

Change-Id: I47a89e4131893b8813b10a6582f8b487b3700b91
diff --git a/cc/makevars.go b/cc/makevars.go
index 6c3f551..70fdd57 100644
--- a/cc/makevars.go
+++ b/cc/makevars.go
@@ -123,6 +123,13 @@
 	ctx.Strict("SOONG_MODULES_USING_WNO_ERROR", makeStringOfKeys(ctx, modulesUsingWnoErrorKey))
 	ctx.Strict("SOONG_MODULES_MISSING_PGO_PROFILE_FILE", makeStringOfKeys(ctx, modulesMissingProfileFileKey))
 
+ 	ctx.Strict("CLANG_COVERAGE_CONFIG_CFLAGS", strings.Join(clangCoverageCFlags, " "))
+ 	ctx.Strict("CLANG_COVERAGE_CONFIG_COMMFLAGS", strings.Join(clangCoverageCommonFlags, " "))
+ 	ctx.Strict("CLANG_COVERAGE_HOST_LDFLAGS", strings.Join(clangCoverageHostLdFlags, " "))
+ 	ctx.Strict("CLANG_COVERAGE_INSTR_PROFILE", profileInstrFlag)
+ 	ctx.Strict("CLANG_COVERAGE_CONTINUOUS_FLAGS", strings.Join(clangContinuousCoverageFlags, " "))
+ 	ctx.Strict("CLANG_COVERAGE_HWASAN_FLAGS", strings.Join(clangCoverageHWASanFlags, " "))
+
 	ctx.Strict("ADDRESS_SANITIZER_CONFIG_EXTRA_CFLAGS", strings.Join(asanCflags, " "))
 	ctx.Strict("ADDRESS_SANITIZER_CONFIG_EXTRA_LDFLAGS", strings.Join(asanLdflags, " "))