Reenable the new pass manager in hwasan builds.

Also remove a deprecated flag -fsanitize-hwaddress-abi=platform.

Switching to the new pass manager reduces size of the "lib64" directory
by almost 6%.

Bug: 135298400
Test: objdump -d path/to/symbols/system/lib64/*.so | grep __hwasan_check_
Test: adb shell sanitizer-status

Change-Id: I327ee982e20c02b3b2126d93189048d9f4bfb301

cc/sanitize.go

@@ -38,8 +38,6 @@ var (
 	asanLdflags = []string{"-Wl,-u,__asan_preinit"}
 
 	hwasanCflags = []string{"-fno-omit-frame-pointer", "-Wno-frame-larger-than=",
-		"-fsanitize-hwaddress-abi=platform",
-		"-fno-experimental-new-pass-manager",
 		// The following improves debug location information
 		// availability at the cost of its accuracy. It increases
 		// the likelihood of a stack variable's frame offset