Fixes more MSan LLVM JIT false positives.

Change-Id: I0579e2cc71b089424fe168cc60fed63c4b431f91
Bug: b/140204746
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/44708
Presubmit-Ready: James Price <jrprice@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: James Price <jrprice@google.com>