Replace 'unsigned short' with 'uint16_t' in a packed data structure for consistency with other fields and to be explicit about bit count.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186796 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/DiagnosticIDs.cpp b/lib/Basic/DiagnosticIDs.cpp
index 898c51c..31e5e6a 100644
--- a/lib/Basic/DiagnosticIDs.cpp
+++ b/lib/Basic/DiagnosticIDs.cpp
@@ -36,7 +36,7 @@
 };
 
 struct StaticDiagInfoRec {
-  unsigned short DiagID;
+  uint16_t DiagID;
   unsigned Mapping : 3;
   unsigned Class : 3;
   unsigned SFINAE : 1;