[Parser] Keep delayed body parsing even with interface hash generation

The generated hash ignores tokens parsed in the body anyway, so there's
no reason to disable delayed body parsing in this case.

Author: bnbarham

lib/AST/Module.cpp

@@ -2348,8 +2348,6 @@ bool SourceFile::hasDelayedBodyParsing() const {
   // Not supported right now.
   if (Kind == SourceFileKind::SIL)
     return false;
-  if (hasInterfaceHash())
-    return false;
   if (shouldCollectTokens())
     return false;
   if (shouldBuildSyntaxTree())