[lld] [lld][ELF] Add --why-live flag (inspired by Mach-O) (PR #127112)

[Fangrui Song via llvm-commits]

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@@ -0,0 +1,132 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -n -filetype=obj -triple=x86_64 %s -o %t.o
+# RUN: echo -e ".globl test_shared\n .section .test_shared,\"ax\", at progbits\n test_shared: jmp test_shared" |\
+# RUN:   llvm-mc -n -filetype=obj -triple=x86_64 -o %t.shared.o
+# RUN: ld.lld -shared %t.shared.o -o %t.so
+
+## Simple live section
+.globl _start
+.section ._start,"ax", at progbits
+_start:
+jmp test_simple
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MaskRay wrote:

indent instructions but keep labels unintended

https://github.com/llvm/llvm-project/pull/127112