[WebAssembly] Update GCC test suite failure expectations

Summary:
Update GCC test suite failure expectations as we add -O0 to the bare tests in
WebAssembly waterfall. There are still several untriaged lld failures.

Reviewers: sbc100, jgravelle-google, dschuff

Reviewed By: dschuff

Subscribers: jfb

Differential Revision: https://reviews.llvm.org/D37100

llvm-svn: 311691