Merge pull request #6380 from akyrtzi/pr/stable/fix-cached-diags

[stable][clang][cas] Fix issues with cached diagnostics

Author: akyrtzi

clang/include/clang/Basic/SourceManager.h

@@ -381,6 +381,11 @@ class ExpansionInfo {
                                        : ExpansionLocEnd;
   }
 
+  /// The actual value of \c ExpansionLocEnd, useful for serialization purposes.
+  SourceLocation getUnderlyingExpansionLocEnd() const {
+    return ExpansionLocEnd;
+  }
+
   bool isExpansionTokenRange() const { return ExpansionIsTokenRange; }
 
   CharSourceRange getExpansionLocRange() const {

clang/test/CAS/cached-diagnostics.c

@@ -70,3 +70,11 @@ PRAG("unknown2")
 void test(int x) {
   if (x=0) {}
 }
+
+#define DEPR _Pragma("GCC warning \"name is deprecated\"")
+#define PARAM "A" DEPR
+#define MAC(x) x
+
+void test2() {
+  (void)MAC(PARAM);
+}