Interned MainFileID within SourceManager. Since SourceManager is referenced by
both Preprocessor and ASTContext, we no longer need to explicitly pass
MainFileID around in function calls that also pass either Preprocessor or
ASTContext. This resulted in some nice cleanups in the ASTConsumers and the
driver.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@45228 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Driver/PrintPreprocessedOutput.cpp b/Driver/PrintPreprocessedOutput.cpp
index 109664b..0c8a62e 100644
--- a/Driver/PrintPreprocessedOutput.cpp
+++ b/Driver/PrintPreprocessedOutput.cpp
@@ -531,7 +531,7 @@
 
 /// DoPrintPreprocessedInput - This implements -E mode.
 ///
-void clang::DoPrintPreprocessedInput(unsigned MainFileID, Preprocessor &PP) {
+void clang::DoPrintPreprocessedInput(Preprocessor &PP) {
   // Inform the preprocessor whether we want it to retain comments or not, due
   // to -C or -CC.
   PP.SetCommentRetentionState(EnableCommentOutput, EnableMacroCommentOutput);
@@ -550,7 +550,7 @@
   // After we have configured the preprocessor, enter the main file.
   
   // Start parsing the specified input file.
-  PP.EnterMainSourceFile(MainFileID);
+  PP.EnterMainSourceFile();
 
   // Consume all of the tokens that come from the predefines buffer.  Those
   // should not be emitted into the output and are guaranteed to be at the