AMDGPU: Pre-commit a test (#166414)

Author: nhaehnle

llvm/test/CodeGen/AMDGPU/finalizebundle.mir

@@ -34,3 +34,16 @@ body: |
     $vgpr0 = V_MOV_B32_e32 $vgpr1, implicit $exec
     dead $vgpr1 = V_MOV_B32_e32 $vgpr0, implicit $exec
 ...
+
+---
+name: test_tied
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: test_tied
+    ; CHECK: BUNDLE implicit-def %0, implicit-def %2, implicit %1:vgpr_32, implicit $mode, implicit $exec {
+    ; CHECK-NEXT:   [[COPY:%[0-9]+]]:vgpr_32 = COPY %1:vgpr_32
+    ; CHECK-NEXT:   [[V_FMAC_F16_e32_:%[0-9]+]]:vgpr_32 = V_FMAC_F16_e32 internal [[COPY]], internal [[COPY]], %1:vgpr_32, implicit $mode, implicit $exec
+    ; CHECK-NEXT: }
+    %1:vgpr_32 = COPY %0:vgpr_32
+    %2:vgpr_32 = V_FMAC_F16_e32 %1, %1, %0, implicit $mode, implicit $exec
+...