OMG tier up checks should be a patchpoint

OMG tier up checks should be a patchpoint
https://bugs.webkit.org/show_bug.cgi?id=172944

Reviewed by Saam Barati.

Tier up checks in BBQ should be done as a patchpoint rather than individual B3 opcodes.
In order to reduce code generated out of line in each function. We generate a single stub
that pushes all the callee-saves. This looks like a 5-10% compile time speedup.

* wasm/WasmB3IRGenerator.cpp:
(JSC::Wasm::B3IRGenerator::B3IRGenerator):
(JSC::Wasm::B3IRGenerator::emitTierUpCheck):
(JSC::Wasm::B3IRGenerator::addLoop):
* wasm/WasmThunks.cpp:
(JSC::Wasm::triggerOMGTierUpThunkGenerator):
* wasm/WasmThunks.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@217812 268f45cc-cd09-0410-ab3c-d52691b4dbfc