[WebAssembly] Narrow the scope of WebAssemblyFixFunctionBitcasts
Summary:
The pass to fix function bitcasts generates thunks for functions that
are called directly with a mismatching signature. It was also generating
thunks in cases where the function was address-taken, causing aliasing
problems in otherwise valid cases.
This patch tightens the restrictions for when the pass runs.
Reviewers: sunfish, dschuff
Subscribers: jfb, sbc100, llvm-commits, aheejin
Differential Revision: https://reviews.llvm.org/D38640
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315326
91177308-0d34-0410-b5e6-
96231b3b80d8