Consolidate some TableGen diagnostic helper functions.

TableGen had diagnostic printers sprinkled about in a few places. Pull them
together into a single location in Error.cpp.

llvm-svn: 133568
diff --git a/llvm/utils/TableGen/DisassemblerEmitter.cpp b/llvm/utils/TableGen/DisassemblerEmitter.cpp
index d68d3b0..07313d1 100644
--- a/llvm/utils/TableGen/DisassemblerEmitter.cpp
+++ b/llvm/utils/TableGen/DisassemblerEmitter.cpp
@@ -9,6 +9,7 @@
 
 #include "DisassemblerEmitter.h"
 #include "CodeGenTarget.h"
+#include "Error.h"
 #include "Record.h"
 #include "X86DisassemblerTables.h"
 #include "X86RecognizableInstr.h"