[llvm] [llvm-objcopy] Fix gap-fill/pad-to tests (PR #75631)

[Fangrui Song via llvm-commits]

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@@ -24,65 +24,65 @@
 ## Test no gap fill with all allocatable output sections.
 # RUN: llvm-objcopy -O binary %t %t-default
 # RUN: od -v -Ax -t x1 %t-default | FileCheck %s --check-prefix=DEFAULT --match-full-lines
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MaskRay wrote:

We may need `--ignore-case` to support z/OS

https://github.com/llvm/llvm-project/pull/75631