[WebAssembly] Remove expected failure from known_gcc_test_failures.txt.  NFC.

Differential Revision: https://reviews.llvm.org/D56809

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351388 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed