Add function attribute 'optnone'.

This function attribute indicates that the function is not optimized
by any optimization or code generator passes with the 
exception of interprocedural optimization passes.

llvm-svn: 189101
diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
index a7d17b7..57834c5 100644
--- a/llvm/include/llvm-c/Core.h
+++ b/llvm/include/llvm-c/Core.h
@@ -165,8 +165,9 @@
        a temporary measure until the API/ABI impact to the C API is understood
        and the path forward agreed upon.
     LLVMAddressSafety = 1ULL << 32,
-    LLVMStackProtectStrongAttribute = 1ULL<<33
-    LLVMCold = 1ULL << 34
+    LLVMStackProtectStrongAttribute = 1ULL<<33,
+    LLVMCold = 1ULL << 34,
+    LLVMOptimizeNone = 1ULL << 35
     */
 } LLVMAttribute;