[llvm] [llvm-objdump][ELF]Fix crash when reading strings from .dynstr(#86612) (PR #125679)

[Fangrui Song via llvm-commits]

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@@ -438,6 +438,9 @@ ProgramHeaders:
 # RUN: yaml2obj --docnum=4 %s -o %t4
 # RUN: llvm-objdump -p %t4 | FileCheck %s --strict-whitespace --check-prefix=INDENT
 
+# RUN: yaml2obj --docnum=5 %s -o %t5
+# RUN: llvm-objdump -p %t5 | FileCheck %s --strict-whitespace --check-prefix=INDENT
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MaskRay wrote:

`2>&1 | FileCheck ...` 

Test both the warning `invalid string table offset` and the output. The output describes how  llvm-objdump handles input input, and is useful as a change detector.

https://github.com/llvm/llvm-project/pull/125679