[Textual SIL] Recognize auto gen'd locations.

Author: nate-chandler

lib/SIL/Parser/ParseSIL.cpp

@@ -2127,8 +2127,14 @@ bool SILParser::parseSILLocation(SILLocation &Loc) {
   if (parseInteger(Column, diag::sil_invalid_column_in_sil_location))
     return true;
 
-  Loc = RegularLocation(SILLocation::FilenameAndLocation::alloc(Line, Column,
-    P.Context.getIdentifier(File).str().data(), SILMod));
+  auto fnl = SILLocation::FilenameAndLocation::alloc(Line, Column,
+    P.Context.getIdentifier(File).str().data(), SILMod);
+
+  Loc = RegularLocation(fnl);
+
+  if (*fnl == *SILLocation::getCompilerGeneratedLoc())
+    Loc.markAutoGenerated();
+
   return false;
 }