[hwasan] remove workaround for fixed toolchain issue

these two upstream commits fixed the issues in global-isel and fast-isel:

* global-isel: https://reviews.llvm.org/D82615
* fast-isel: https://reviews.llvm.org/D138615

Currently used clang r498229 (defined build/soong/cc/config/global.go)
is based on upstream commit 14f0776550b5a49e1c42f49a00213f7f3fa047bf
which includes these two changes.

Bug: 293297826
Test: build oriole_hwasan and boot
Change-Id: I65fabdf0b5edd248b4bf4e138a999f8142370cd5

cc/sanitize.go

@@ -56,10 +56,6 @@ var (
 		// higher number of "optimized out" stack variables.
 		// b/112437883.
 		"-instcombine-lower-dbg-declare=0",
-		// TODO(b/159343917): HWASan and GlobalISel don't play nicely, and
-		// GlobalISel is the default at -O0 on aarch64.
-		"--aarch64-enable-global-isel-at-O=-1",
-		"-fast-isel=false",
 		"-hwasan-use-after-scope=1",
 		"-dom-tree-reachability-max-bbs-to-explore=128",
 	}