Clean up language and grammar.

Based on a patch by jfcaron3@gmail.com!
PR19806

llvm-svn: 209216
diff --git a/llvm/lib/Support/Windows/DynamicLibrary.inc b/llvm/lib/Support/Windows/DynamicLibrary.inc
index 504471e..5d0278f 100644
--- a/llvm/lib/Support/Windows/DynamicLibrary.inc
+++ b/llvm/lib/Support/Windows/DynamicLibrary.inc
@@ -58,7 +58,7 @@
         stricmp(ModuleName, "msvcr70") != 0 &&
 #ifndef __MINGW32__
         // Mingw32 uses msvcrt.dll by default. Don't ignore it.
-        // Otherwise, user should be aware, what he's doing :)
+        // Otherwise the user should be aware what they are doing.
         stricmp(ModuleName, "msvcrt") != 0 &&
 #endif
         stricmp(ModuleName, "msvcrt20") != 0 &&