Split arguments to C1ERKS copy assignment

This patch splits the parameters going into the copy assignment from
`instance2` into `instance`.

Some builds of the compiler are emitting additional annotations on the
pointer.

The resulting parameters on Linux (on my box anyway) look like this:
`(%struct.NonTrivialCopyAndCopyMoveAssign* noundef nonnull align 4 dereferenceable(5) %2, %struct.NonTrivialCopyAndCopyMoveAssign* noundef nonnull align 4 dereferenceable(5) %4)`

These annotations look reasonable, but they don't show up on macOS.
I've added check-same to ensure that the parameter passing is still
happening while ignoring the additional annotations.

Author: etcwilde

test/Interop/Cxx/class/copy-move-assignment-irgen.swift

@@ -20,7 +20,10 @@ public func copyAssign() {
 // CHECK: call {{void|\%struct.NonTrivialCopyAndCopyMoveAssign\*}} @{{_ZN31NonTrivialCopyAndCopyMoveAssignC1Ev|_ZN31NonTrivialCopyAndCopyMoveAssignC2Ev|"\?\?0NonTrivialCopyAndCopyMoveAssign@@QEAA@XZ"}}(%struct.NonTrivialCopyAndCopyMoveAssign* %[[COPY_INSTANCE:.*]])
 // CHECK: call {{void|\%struct.NonTrivialCopyAndCopyMoveAssign\*}} @{{_ZN31NonTrivialCopyAndCopyMoveAssignC1Ev|_ZN31NonTrivialCopyAndCopyMoveAssignC2Ev|"\?\?0NonTrivialCopyAndCopyMoveAssign@@QEAA@XZ"}}(%struct.NonTrivialCopyAndCopyMoveAssign* %[[COPY_INSTANCE2:.*]])
 // CHECK: call {{void|\%struct.NonTrivialCopyAndCopyMoveAssign\*}} @{{_ZN31NonTrivialCopyAndCopyMoveAssignD1Ev|_ZN31NonTrivialCopyAndCopyMoveAssignD2Ev|"\?\?1NonTrivialCopyAndCopyMoveAssign@@QEAA@XZ"}}(%struct.NonTrivialCopyAndCopyMoveAssign* %[[COPY_INSTANCE]])
-// CHECK: call {{void|\%struct.NonTrivialCopyAndCopyMoveAssign\*}} @{{_ZN31NonTrivialCopyAndCopyMoveAssignC1ERKS_|_ZN31NonTrivialCopyAndCopyMoveAssignC2ERKS_|"\?\?0NonTrivialCopyAndCopyMoveAssign@@QEAA@AEBU0@@Z"}}(%struct.NonTrivialCopyAndCopyMoveAssign* %[[COPY_INSTANCE]], %struct.NonTrivialCopyAndCopyMoveAssign* %[[COPY_INSTANCE2]])
+// CHECK: call {{void|\%struct.NonTrivialCopyAndCopyMoveAssign\*}} @{{_ZN31NonTrivialCopyAndCopyMoveAssignC1ERKS_|_ZN31NonTrivialCopyAndCopyMoveAssignC2ERKS_|"\?\?0NonTrivialCopyAndCopyMoveAssign@@QEAA@AEBU0@@Z"}}(%struct.NonTrivialCopyAndCopyMoveAssign*
+// CHECK-SAME: %[[COPY_INSTANCE]],
+// CHECK-SAME: %struct.NonTrivialCopyAndCopyMoveAssign*
+// CHECK-SAME: %[[COPY_INSTANCE2]])
 // CHECK: call {{.*}} @{{_ZN31NonTrivialCopyAndCopyMoveAssignD1Ev|_ZN31NonTrivialCopyAndCopyMoveAssignD2Ev|"\?\?1NonTrivialCopyAndCopyMoveAssign@@QEAA@XZ"}}(%struct.NonTrivialCopyAndCopyMoveAssign* %[[COPY_INSTANCE2]])
 // CHECK: call {{.*}} @{{_ZN31NonTrivialCopyAndCopyMoveAssignD1Ev|_ZN31NonTrivialCopyAndCopyMoveAssignD2Ev|"\?\?1NonTrivialCopyAndCopyMoveAssign@@QEAA@XZ"}}(%struct.NonTrivialCopyAndCopyMoveAssign* %[[COPY_INSTANCE]])