[Parser] Parse pops (by doing nothing) (#6252)

Parse pop expressions and check that they have the expected types, but do not
actually create new Pop expressions or push anything onto the stack because we
already create Pop expressions as necessary when visiting the beginning of catch
blocks.

Unlike the legacy text parser, the new text parser is not capable of parsing
pops in invalid locations in the IR. This means that the new text parser will
never be able to parse test/lit/catch-pop-fixup-eh-old.wast, which deliberately
parses invalid IR to check that the pops can be fixed up and moved to the
correct locations. It should be acceptable to delete that test when we turn on
the new parser by default, though, so that won't be a problem.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/parser/parsers.h b/src/parser/parsers.h
index 706c6525e..c7b9168b1 100644
--- a/src/parser/parsers.h
+++ b/src/parser/parsers.h
@@ -1555,7 +1555,9 @@ template<typename Ctx> Result<> makeMemoryFill(Ctx& ctx, Index pos) {
 }
 
 template<typename Ctx> Result<> makePop(Ctx& ctx, Index pos) {
-  return ctx.in.err("unimplemented instruction");
+  auto type = valtype(ctx);
+  CHECK_ERR(type);
+  return ctx.makePop(pos, *type);
 }
 
 template<typename Ctx> Result<> makeCall(Ctx& ctx, Index pos, bool isReturn) {