[llvm] [LV][NFC] Remove use of -print-after=... to verify IR output (PR #194882)

[David Sherwood via llvm-commits]

================
@@ -1,12 +1,13 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals none --filter-out-after "scalar.ph\:" --version 5
 ; REQUIRES: asserts
-; RUN: opt < %s -aa-pipeline=basic-aa -passes=loop-vectorize,instcombine -S -debug-only=loop-vectorize -disable-output -print-after=instcombine 2>&1 | FileCheck %s
+; RUN: opt < %s -aa-pipeline=basic-aa -passes=loop-vectorize,instcombine -S -debug-only=loop-vectorize 2>%t -S | FileCheck %s
+; RUN: cat %t | FileCheck %s --check-prefix=DEBUG
 ; RUN: opt < %s -passes=loop-vectorize -force-vector-width=2 -S | FileCheck %s -check-prefix=FORCE
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
-; CHECK-LABEL: PR31671
+; DEBUG-LABEL: PR31671
----------------
david-arm wrote:

Yeah, it gets skipped. This is the output from the script:

```
WARNING: Skipping non-opt RUN line: cat %t | FileCheck %s --check-prefix=DEBUG
```

https://github.com/llvm/llvm-project/pull/194882