[WebAssembly] Add isEHScopeReturn instruction property

Summary:
So far, `isReturn` property is used to mean both a return instruction
from a functon and the end of an EH scope, a scope that starts with a EH
scope entry BB and ends with a catchret or a cleanupret instruction.
Because WinEH uses funclets, all EH-scope-ending instructions are also
real return instruction from a function. But for wasm, they only serve
as the end marker of an EH scope but not a return instruction that
exits a function. This mismatch caused incorrect prolog and epilog
generation in wasm EH scopes. This patch fixes this.

This patch is in the same vein with rL333045, which splits
`MachineBasicBlock::isEHFuncletEntry` into `isEHFuncletEntry` and
`isEHScopeEntry`.

Reviewers: dschuff

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

Differential Revision: https://reviews.llvm.org/D50653

llvm-svn: 340325

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/utils/TableGen/InstrDocsEmitter.cpp b/llvm/utils/TableGen/InstrDocsEmitter.cpp
index 65cb28cd17a..41dc37a7ab3 100644
--- a/llvm/utils/TableGen/InstrDocsEmitter.cpp
+++ b/llvm/utils/TableGen/InstrDocsEmitter.cpp
@@ -100,6 +100,7 @@ void EmitInstrDocs(RecordKeeper &RK, raw_ostream &OS) {
 #define str(s) #s
 #define FLAG(f) if (II->f) { FlagStrings.push_back(str(f)); }
     FLAG(isReturn)
+    FLAG(isEHScopeReturn)
     FLAG(isBranch)
     FLAG(isIndirectBranch)
     FLAG(isCompare)