SourceManager: Use setMainFileID() consistently

Eliminate createMainFileID() / createMainFileIDForMemBuffer() utility
functions. These didn't add much convenience and conflated two distinct
operations.

This change makes things easier to follow by providing a consistent interface
and getting rid of a bunch of cast-to-voids.

llvm-svn: 209266
diff --git a/clang/unittests/Lex/LexerTest.cpp b/clang/unittests/Lex/LexerTest.cpp
index 7be9360..3d30352 100644
--- a/clang/unittests/Lex/LexerTest.cpp
+++ b/clang/unittests/Lex/LexerTest.cpp
@@ -64,7 +64,7 @@
   std::vector<Token> CheckLex(StringRef Source,
                               ArrayRef<tok::TokenKind> ExpectedTokens) {
     MemoryBuffer *buf = MemoryBuffer::getMemBuffer(Source);
-    (void) SourceMgr.createMainFileIDForMemBuffer(buf);
+    SourceMgr.setMainFileID(SourceMgr.createFileID(buf));
 
     VoidModuleLoader ModLoader;
     HeaderSearch HeaderInfo(new HeaderSearchOptions, SourceMgr, Diags, LangOpts,
diff --git a/clang/unittests/Lex/PPCallbacksTest.cpp b/clang/unittests/Lex/PPCallbacksTest.cpp
index 25dc7db..cceebea 100644
--- a/clang/unittests/Lex/PPCallbacksTest.cpp
+++ b/clang/unittests/Lex/PPCallbacksTest.cpp
@@ -163,7 +163,7 @@
   CharSourceRange InclusionDirectiveFilenameRange(const char* SourceText, 
       const char* HeaderPath, bool SystemHeader) {
     MemoryBuffer *Buf = MemoryBuffer::getMemBuffer(SourceText);
-    (void)SourceMgr.createMainFileIDForMemBuffer(Buf);
+    SourceMgr.setMainFileID(SourceMgr.createFileID(Buf));
 
     VoidModuleLoader ModLoader;
 
@@ -200,7 +200,7 @@
     OpenCLLangOpts.OpenCL = 1;
 
     MemoryBuffer* sourceBuf = MemoryBuffer::getMemBuffer(SourceText, "test.cl");
-    (void)SourceMgr.createMainFileIDForMemBuffer(sourceBuf);
+    SourceMgr.setMainFileID(SourceMgr.createFileID(sourceBuf));
 
     VoidModuleLoader ModLoader;
     HeaderSearch HeaderInfo(new HeaderSearchOptions, SourceMgr, Diags, 
diff --git a/clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp b/clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
index ff81fa0..f7ed8e5 100644
--- a/clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
+++ b/clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
@@ -92,7 +92,7 @@
       "9\n";
 
   MemoryBuffer *buf = MemoryBuffer::getMemBuffer(source);
-  SourceMgr.createMainFileIDForMemBuffer(buf);
+  SourceMgr.setMainFileID(SourceMgr.createFileID(buf));
 
   VoidModuleLoader ModLoader;
   HeaderSearch HeaderInfo(new HeaderSearchOptions, SourceMgr, Diags, LangOpts,