[Wasm Exceptions] Fix/work around delegate issues in Inlining pass (#3633)

1. Ignore the fake delegate target in the unique name mapper. The mapper
    is run after inlining, so this fixes inlining into a function that has a delegate
    to the caller.

2. Do not inline a function with a delegate. We should support this eventually,
    but for now I think this is good enough.

After this Inlining should be safe to run on exceptions code.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/parsing.h b/src/parsing.h
index 9c3e0cd19..a8ed8b13f 100644
--- a/src/parsing.h
+++ b/src/parsing.h
@@ -321,6 +321,11 @@ struct UniqueNameMapper {
   }
 
   Name sourceToUnique(Name sName) {
+    // DELEGATE_CALLER_TARGET is a fake target used to denote delegating to the
+    // caller. We do not need to modify it, as it has no definitions, only uses.
+    if (sName == DELEGATE_CALLER_TARGET) {
+      return DELEGATE_CALLER_TARGET;
+    }
     if (labelMappings.find(sName) == labelMappings.end()) {
       throw ParseException("bad label in sourceToUnique");
     }