[WebAssembly] Add hasSideEffects flag to catch instructions

Summary:
`catch` instruction certainly has rather huge side effects and the flag
was missing. At the moment this does not change any unit tests we
currently have.

Reviewers: dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D50919

llvm-svn: 340433

llvm/lib/Target/WebAssembly/WebAssemblyInstrControl.td

@@ -172,7 +172,7 @@ defm END_TRY : NRI<(outs), (ins), [], "end_try", 0x0b>;
 } // Uses = [VALUE_STACK], Defs = [VALUE_STACK]
 
 // Catching an exception: catch / catch_all
-let hasCtrlDep = 1 in {
+let hasCtrlDep = 1, hasSideEffects = 1 in {
 defm CATCH_I32 : I<(outs I32:$dst), (ins i32imm:$tag),
                    (outs), (ins i32imm:$tag),
                    [(set I32:$dst, (int_wasm_catch imm:$tag))],