Fix some remaining documentation references to MSVC 2013

MSVC 2015 has been the minimum supported version of VS since October.

Differential Revision: https://reviews.llvm.org/D25710

llvm-svn: 289854
diff --git a/llvm/cmake/modules/CheckCompilerVersion.cmake b/llvm/cmake/modules/CheckCompilerVersion.cmake
index 1c046ad..cdad7ce2 100644
--- a/llvm/cmake/modules/CheckCompilerVersion.cmake
+++ b/llvm/cmake/modules/CheckCompilerVersion.cmake
@@ -1,5 +1,5 @@
 # Check if the host compiler is new enough. LLVM requires at least GCC 4.8,
-# MSVC 2013, or Clang 3.1.
+# MSVC 2015 (Update 3), or Clang 3.1.
 
 include(CheckCXXSourceCompiles)
 
@@ -17,8 +17,8 @@
       endif()
 
       if (CMAKE_CXX_SIMULATE_ID MATCHES "MSVC")
-        if (CMAKE_CXX_SIMULATE_VERSION VERSION_LESS 18.0)
-          message(FATAL_ERROR "Host Clang must have at least -fms-compatibility-version=18.0")
+        if (CMAKE_CXX_SIMULATE_VERSION VERSION_LESS 19.0)
+          message(FATAL_ERROR "Host Clang must have at least -fms-compatibility-version=19.0")
         endif()
         set(CLANG_CL 1)
       elseif(NOT LLVM_ENABLE_LIBCXX)
@@ -41,10 +41,10 @@
         set(CMAKE_REQUIRED_LIBRARIES ${OLD_CMAKE_REQUIRED_LIBRARIES})
       endif()
     elseif(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
-      if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 18.0)
-        message(FATAL_ERROR "Host Visual Studio must be at least 2013")
-      elseif(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 18.0.31101)
-        message(WARNING "Host Visual Studio should at least be 2013 Update 4 (MSVC 18.0.31101)"
+      if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.0)
+        message(FATAL_ERROR "Host Visual Studio must be at least 2015")
+      elseif(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.00.24215.1)
+        message(WARNING "Host Visual Studio should at least be 2015 Update 3 (MSVC 19.00.24215.1)"
           "  due to miscompiles from earlier versions")
       endif()
     endif()