[Parse] Don't update interface hash unless parsing interface tokens

Previously, parsing function bodies used to update interface hash
regardless of the flag. Parsing local function should not update it.

Author: rintaro

lib/Parse/ParseDecl.cpp

@@ -5354,9 +5354,11 @@ void Parser::parseAbstractFunctionBody(AbstractFunctionDecl *AFD) {
     return;
   }
 
-  // Record the curly braces but nothing inside.
-  SF.recordInterfaceToken("{");
-  SF.recordInterfaceToken("}");
+  if (IsParsingInterfaceTokens) {
+    // Record the curly braces but nothing inside.
+    SF.recordInterfaceToken("{");
+    SF.recordInterfaceToken("}");
+  }
   llvm::SaveAndRestore<bool> T(IsParsingInterfaceTokens, false);
 
   if (isDelayedParsingEnabled()) {

test/InterfaceHash/added_localfunc.swift

@@ -0,0 +1,18 @@
+// RUN: %empty-directory(%t)
+// RUN: %{python} %utils/split_file.py -o %t %s
+// RUN: %target-swift-frontend -dump-interface-hash %t/a.swift 2> %t/a.hash
+// RUN: %target-swift-frontend -dump-interface-hash %t/b.swift 2> %t/b.hash
+// RUN: cmp %t/a.hash %t/b.hash
+
+// BEGIN a.swift
+func test() -> Int {
+  return 0
+}
+
+// BEGIN b.swift
+func test() -> Int {
+  func inner() -> Int{
+    return 0
+  }
+  return inner()
+}