[asan][windows] Weak function interception support in instruction size decoder. (#86570)

This makes it so we'll be able to decode the instructions used in the
weak function stubs from
https://github.com/llvm/llvm-project/pull/81677. This code doesn't
technically require those changes.

Co-authored-by: Amy Wishnousky <amyw@microsoft.com>
GitOrigin-RevId: 423832421b9b259612c3fe4169a6a6e1e2600f95
1 file changed