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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189101 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Feature/optnone.ll b/test/Feature/optnone.ll
new file mode 100644
index 0000000..ec1d723
--- /dev/null
+++ b/test/Feature/optnone.ll
@@ -0,0 +1,12 @@
+; RUN: llvm-as < %s | llvm-dis | FileCheck %s
+
+; Check for the presence of attribute noopt in the disassembly.
+
+; CHECK: @foo() #0
+define void @foo() #0 {
+  ret void
+}
+
+; CHECK: attributes #0 = { optnone }
+attributes #0 = { optnone }
+