Factor some of the constants+context related code out into a separate header, to make LLVMContextImpl.h
not hideous.  Also, fix some MSVC compile errors.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78115 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Reader/BitcodeReader.h b/lib/Bitcode/Reader/BitcodeReader.h
index bd04888..a1f9113 100644
--- a/lib/Bitcode/Reader/BitcodeReader.h
+++ b/lib/Bitcode/Reader/BitcodeReader.h
@@ -26,7 +26,7 @@
 
 namespace llvm {
   class MemoryBuffer;
-  class LLVMContext;
+  struct LLVMContext;
   
 //===----------------------------------------------------------------------===//
 //                          BitcodeReaderValueList Class