[lld] [lld-macho] Save all thin archive members in repro tarball (PR #97169)

[Fangrui Song via llvm-commits]

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@@ -0,0 +1,25 @@
+# REQUIRES: x86
+
+## For a long time, LLD only included those members from thin archives that were actually used
+## during linking. However, we need to iterate over all members for -ObjC, check that we don't
+## crash when we encounter a missing member.
+
+# RUN: rm -rf %t; mkdir %t
+# RUN: sed s/SYM/_main/   %s | llvm-mc -filetype=obj -triple=x86_64-apple-macos -o %t/main.o
+# RUN: sed s/SYM/_unused/ %s | llvm-mc -filetype=obj -triple=x86_64-apple-macos -o %t/unused.o
+
+# RUN: cd %t; llvm-ar rcsT unused.a unused.o; rm unused.o
+## FIXME: Absolute paths don't end up relativized in the repro file.
+
+# RUN: %no-fatal-warnings-lld %t/main.o %t/unused.a -ObjC -o /dev/null 2>&1 \
+# RUN:                      | FileCheck %s --check-prefix=WARN
+
+# RUN: %lld %t/main.o %t/unused.a -ObjC --no-warn-thin-archive-missing-members -o /dev/null \
+# RUN:    | FileCheck %s --implicit-check-not 'warning' --allow-empty
+
+# WARN: ld64.lld: warning: {{.*}}unused.a: -ObjC failed to open archive member: 'unused.o'
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MaskRay wrote:

Made some adjustment to hopefully make the test more conventional 2d756d9d4c89ac50404f942f2db2f4a402aa0e00

https://github.com/llvm/llvm-project/pull/97169