[coverage] On coverage+hwasan build, disable hwasan global instrumentation

Bug: http://b/248022906
Bug: http://b/247941801

HWAsan global instrumentation on __llvm_profile_filename causes
duplicate symbol errors when linked together with libraries where hwasan
is disabled.  Disable hwasan global instrumentation since those type of
errors are rare.

In the future, we may fix this in llvm to skip hwasan global
instrumentation on symbols added for coverage.

Test: m CLANG_COVERAGE=true NATIVE_COVERAGE_PATHS=* \
          SANITIZE_TARGET=hwaddress
Test: Add `hwaddress: true` to libc_defaults; m CLANG_COVERAGE=true

Change-Id: I8506cfd567d212262a2a54b9881a8f64cdbf7a76

cc/coverage.go

@@ -108,6 +108,12 @@ func (cov *coverage) flags(ctx ModuleContext, flags Flags, deps PathDeps) (Flags
 			if EnableContinuousCoverage(ctx) {
 				flags.Local.CommonFlags = append(flags.Local.CommonFlags, "-mllvm", "-runtime-counter-relocation")
 			}
+
+			// http://b/248022906, http://b/247941801  enabling coverage and hwasan-globals
+			// instrumentation together causes duplicate-symbol errors for __llvm_profile_filename.
+			if c, ok := ctx.Module().(*Module); ok && c.sanitize.isSanitizerEnabled(Hwasan) {
+				flags.Local.CommonFlags = append(flags.Local.CommonFlags, "-mllvm", "-hwasan-globals=0")
+			}
 		}
 	}