Update Compiler.h to fail fast when building with MSVC 2013

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284665 91177308-0d34-0410-b5e6-96231b3b80d8

Author: rnk

include/llvm/Support/Compiler.h

@@ -60,14 +60,13 @@
 /// \macro LLVM_MSC_PREREQ
 /// \brief Is the compiler MSVC of at least the specified version?
 /// The common \param version values to check for are:
-///  * 1800: Microsoft Visual Studio 2013 / 12.0
 ///  * 1900: Microsoft Visual Studio 2015 / 14.0
 #ifdef _MSC_VER
 #define LLVM_MSC_PREREQ(version) (_MSC_VER >= (version))
 
-// We require at least MSVC 2013.
-#if !LLVM_MSC_PREREQ(1800)
-#error LLVM requires at least MSVC 2013.
+// We require at least MSVC 2015.
+#if !LLVM_MSC_PREREQ(1900)
+#error LLVM requires at least MSVC 2015.
 #endif
 
 #else