[llvm] [NFC][AMDGPU][Attributor] Exit earlier if entry CC (PR #114177)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `premerge-monolithic-linux` running on `premerge-linux-1` while building `llvm` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/153/builds/13122

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 7 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: CodeGen/AMDGPU/propagate-waves-per-eu.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 2: /build/buildbot/premerge-monolithic-linux/build/bin/opt -S -mtriple=amdgcn-amd-amdhsa -passes=amdgpu-attributor /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AMDGPU/propagate-waves-per-eu.ll | /build/buildbot/premerge-monolithic-linux/build/bin/FileCheck /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AMDGPU/propagate-waves-per-eu.ll
+ /build/buildbot/premerge-monolithic-linux/build/bin/FileCheck /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AMDGPU/propagate-waves-per-eu.ll
+ /build/buildbot/premerge-monolithic-linux/build/bin/opt -S -mtriple=amdgcn-amd-amdhsa -passes=amdgpu-attributor /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AMDGPU/propagate-waves-per-eu.ll
/build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AMDGPU/propagate-waves-per-eu.ll:17:15: error: CHECK-SAME: expected string not found in input
; CHECK-SAME: () #[[ATTR0]] {
              ^
<stdin>:10:38: note: scanning from here
define amdgpu_kernel void @kernel_1_8() #1 {
                                     ^
<stdin>:10:38: note: with "ATTR0" equal to "0"
define amdgpu_kernel void @kernel_1_8() #1 {
                                     ^
/build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AMDGPU/propagate-waves-per-eu.ll:36:15: error: CHECK-SAME: expected string not found in input
; CHECK-SAME: () #[[ATTR1]] {
              ^
<stdin>:19:38: note: scanning from here
define amdgpu_kernel void @kernel_1_2() #2 {
                                     ^
<stdin>:19:38: note: with "ATTR1" equal to "0"
define amdgpu_kernel void @kernel_1_2() #2 {
                                     ^
/build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AMDGPU/propagate-waves-per-eu.ll:61:15: error: CHECK-SAME: expected string not found in input
; CHECK-SAME: () #[[ATTR2]] {
              ^
<stdin>:31:38: note: scanning from here
define amdgpu_kernel void @kernel_1_4() #3 {
                                     ^
<stdin>:31:38: note: with "ATTR2" equal to "0"
define amdgpu_kernel void @kernel_1_4() #3 {
                                     ^
/build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AMDGPU/propagate-waves-per-eu.ll:108:15: error: CHECK-SAME: expected string not found in input
; CHECK-SAME: () #[[ATTR3]] {
              ^
<stdin>:52:38: note: scanning from here
define amdgpu_kernel void @kernel_2_9() #7 {
                                     ^
<stdin>:52:38: note: with "ATTR3" equal to "0"
define amdgpu_kernel void @kernel_2_9() #7 {
                                     ^
/build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AMDGPU/propagate-waves-per-eu.ll:120:15: error: CHECK-SAME: expected string not found in input
; CHECK-SAME: () #[[ATTR6]] {
              ^
<stdin>:58:38: note: scanning from here
define amdgpu_kernel void @kernel_9_9() #8 {
                                     ^
...

```

</details>

https://github.com/llvm/llvm-project/pull/114177