Update comment for msvcrt CMake option

(cherry picked from commit 9a0e88a016ce7ad5d013c42b6a272aff1cb5aad1)

CMakeLists.txt

@@ -67,7 +67,8 @@ if (GLFW_BUILD_DOCS)
 endif()
 
 #--------------------------------------------------------------------
-# Set compiler specific flags
+# Apply Microsoft C runtime library option
+# This is here because it also applies to tests and examples
 #--------------------------------------------------------------------
 if (MSVC)
     if (MSVC90)