[fixcode] Accept the fixit for adding bang to unwrap optional.

This is useful for getting fixits for the IOU handling changes.

Author: akyrtzi

lib/FrontendTool/FrontendTool.cpp

@@ -554,11 +554,6 @@ class JSONFixitWriter : public DiagnosticConsumer {
     if (FixitAll)
       return true;
 
-    // Err on the side of caution and don't automatically add bang, which may
-    // lead to crashes.
-    if (Info.ID == diag::missing_unwrap_optional.ID)
-      return false;
-
     // Do not add a semi as it is wrong in most cases during migration
     if (Info.ID == diag::statement_same_line_without_semi.ID)
       return false;

test/FixCode/fixits-apply.swift

@@ -11,7 +11,7 @@ b as Derived
 b as! Base
 
 var opti : Int?
-// Don't add bang.
+// Add bang.
 var i : Int = opti
 // But remove unnecessary bang.
 var i2 : Int = i!

test/FixCode/fixits-apply.swift.result

@@ -11,8 +11,8 @@ b as! Derived
 b 
 
 var opti : Int?
-// Don't add bang.
-var i : Int = opti
+// Add bang.
+var i : Int = opti!
 // But remove unnecessary bang.
 var i2 : Int = i