Add missed test

Author: asb

mlir/test/Target/LLVMIR/unsafe-fp-math.mlir

@@ -0,0 +1,8 @@
+// RUN: mlir-translate -mlir-to-llvmir %s | FileCheck %s
+
+// CHECK-LABEL: define void @unsafe_fp_math_func() 
+// CHECK-SAME: #[[ATTRS:[0-9]+]]
+llvm.func @unsafe_fp_math_func() attributes {unsafe_fp_math = true}  {
+  llvm.return
+}
+// CHECK: attributes #[[ATTRS]] = { "unsafe-fp-math"="true" }