[lld/test/ELF] Test fetch from archive to resolve undefined symbols in shared libs

Add missing test coverage uncovered in review of D108006.

Differential Revision: https://reviews.llvm.org/D108328

lld/test/ELF/dso-undef-extract-lazy.s

@@ -0,0 +1,40 @@
+# REQUIRES: x86
+# RUN: rm -fr %t && split-file %s %t
+
+## Build an object with a trivial main function
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %t/main.s -o %t1.o
+
+## Build %t.a which defines a global 'foo'
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %t/archive.s -o %t2.o
+# RUN: rm -f %t2.a
+# RUN: llvm-ar rc %t2.a %t2.o
+
+## Build %t.so that has a reference to 'foo'
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %t/shlib.s -o %t3.o
+# RUN: ld.lld %t3.o -o %t3.so -shared
+
+## Test that 'foo' from %t2.a is fetched to define 'foo' needed by %t3.so.
+## Test both cases where the archive is before or after the shared library in
+## link order.
+
+# RUN: ld.lld %t1.o %t2.a %t3.so -o %t.exe
+# RUN: llvm-readelf --dyn-symbols %t.exe | FileCheck %s --check-prefix=CHECK-FETCH
+
+# RUN: ld.lld %t1.o %t3.so %t2.a -o %t.exe
+# RUN: llvm-readelf --dyn-symbols %t.exe | FileCheck %s --check-prefix=CHECK-FETCH
+
+# CHECK-FETCH: GLOBAL DEFAULT {{[0-9]+}} foo
+
+#--- main.s
+.text
+.globl _start
+.type _start,@function
+_start:
+  ret
+
+#--- archive.s
+.global foo
+foo:
+
+#--- shlib.s
+.global foo