Reland "[hwasan] remove workaround for fixed toolchain issue"

This reverts commit e72ee14006.

Bug: 293532332
Reason for revert: Test failure fixed in https://r.android.com/2681595

Change-Id: Id40079133e50492a6e2f3e2794012695562c39f6

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",
 	}