[turbofan] Return constant type for functions with unknown parameter count.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1221753002

Cr-Commit-Position: refs/heads/master@{#29364}

src/compiler/typer.cc

@@ -2365,7 +2365,7 @@ Type* Typer::Visitor::TypeConstant(Handle<Object> value) {
     switch (arity) {
       case SharedFunctionInfo::kDontAdaptArgumentsSentinel:
         // Some smart optimization at work... &%$!&@+$!
-        return Type::Any(zone());
+        break;
       case 0:
         return typer_->cache_.kAnyFunc0;
       case 1: