[TypedFunctionReferences] Enable call_ref in fuzzer, and fix minor misc fuzz bugs (#3401)

* Count signatures in tuple locals.
* Count nested signature types (confirming @aheejin was right, that was missing).
* Inlining was using the wrong type.
* OptimizeInstructions should return -1 for unhandled types, not error.
* The fuzzer should check for ref types as well, not just typed function references,
  similar to what GC does.
* The fuzzer now creates a function if it has no other option for creating a constant
  expression of a function type, then does a ref.func of that.
* Handle unreachability in call_ref binary reading.
* S-expression parsing fixes in more places, and add a tiny fuzzer for it.
* Switch fuzzer test to just have the metrics, and not print all the fuzz output which
  changes a lot. Also fix noprint handling which only worked on binaries before.
* Fix Properties::getLiteral() to use the specific function type properly, and make
  Literal's function constructor require that, to prevent future bugs.
* Turn all input types into nullable types, for now.

1 files changed, 8 insertions, 2 deletions

diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
index 864a46362..33b34904e 100644
--- a/src/passes/Print.cpp
+++ b/src/passes/Print.cpp
@@ -103,15 +103,21 @@ std::ostream& operator<<(std::ostream& os, SigName sigName) {
             if (t.isNullable()) {
               os << "_null";
             }
-            os << "<";
+            os << "[";
+            auto subsep = "";
             for (auto s : sig.params) {
+              os << subsep;
+              subsep = "_";
               printType(s);
             }
             os << "_->_";
+            subsep = "";
             for (auto s : sig.results) {
+              os << subsep;
+              subsep = "_";
               printType(s);
             }
-            os << ">";
+            os << "]";
             continue;
           }
         }