[nfc][cxx-interop] Fix regex in reference irgen test.

We shouldn't rely on the specific name of the operand.

Author: zoecarver

test/Interop/Cxx/reference/reference-irgen.swift

@@ -36,28 +36,28 @@ public func setCxxRef() {
 }
 
 // CHECK: define {{(protected |dllexport )?}}swiftcc void @"$s4main9setCxxRefyyF"()
-// CHECK: call void @{{_Z15setStaticIntRefRi|"\?setStaticIntRef@@YAXAEAH@Z"}}(i32* {{nonnull %val|%2}})
+// CHECK: call void @{{_Z15setStaticIntRefRi|"\?setStaticIntRef@@YAXAEAH@Z"}}(i32* %{{.*}})
 
 public func setCxxConstRef() {
   var val: CInt = 21
   setConstStaticIntRef(&val)
 }
 
 // CHECK: define {{(protected |dllexport )?}}swiftcc void @"$s4main14setCxxConstRefyyF"()
-// CHECK: call void @{{_Z20setConstStaticIntRefRKi|"\?setConstStaticIntRef@@YAXAEBH@Z"}}(i32* {{nonnull %val|%2}})
+// CHECK: call void @{{_Z20setConstStaticIntRefRKi|"\?setConstStaticIntRef@@YAXAEBH@Z"}}(i32* %{{.*}})
 
 public func setCxxRvalueRef() {
   var val: CInt = 21
   setStaticIntRvalueRef(&val)
 }
 
 // CHECK: define {{(protected |dllexport )?}}swiftcc void @"$s4main15setCxxRvalueRefyyF"()
-// CHECK: call void @{{_Z21setStaticIntRvalueRefOi|"\?setStaticIntRvalueRef@@YAX\$\$QEAH@Z"}}(i32* {{nonnull %val|%2}})
+// CHECK: call void @{{_Z21setStaticIntRvalueRefOi|"\?setStaticIntRvalueRef@@YAX\$\$QEAH@Z"}}(i32* %{{.*}})
 
 public func setCxxConstRvalueRef() {
   var val: CInt = 21
   setConstStaticIntRvalueRef(&val)
 }
 
 // CHECK: define {{(protected |dllexport )?}}swiftcc void @"$s4main20setCxxConstRvalueRefyyF"()
-// CHECK: call void @{{_Z26setConstStaticIntRvalueRefOKi|"\?setConstStaticIntRvalueRef@@YAX\$\$QEBH@Z"}}(i32* {{nonnull %val|%2}})
+// CHECK: call void @{{_Z26setConstStaticIntRvalueRefOKi|"\?setConstStaticIntRvalueRef@@YAX\$\$QEBH@Z"}}(i32* %{{.*}})