Add 'nonnull', a new parameter and return attribute which indicates that the pointer is not null. Instcombine will elide comparisons between these and null. Patch by Luqman Aden!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209185 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Bitcode/LLVMBitCodes.h

@@ -371,7 +371,8 @@ namespace bitc {
     ATTR_KIND_BUILTIN = 35,
     ATTR_KIND_COLD = 36,
     ATTR_KIND_OPTIMIZE_NONE = 37,
-    ATTR_KIND_IN_ALLOCA = 38
+    ATTR_KIND_IN_ALLOCA = 38,
+    ATTR_KIND_NON_NULL = 39
   };
 
 } // End bitc namespace