tests: Test extern'd globals on MacOS with the Apple Archiver

This is a regression test for:
#11165.

The test was initially merged as part of:
#10628, but had to be reverted.

A second attempt at fixing the root cause also had to be reverted:
#10699.

A 3rd attempt got merged but missed this unit test:
#11742.

Co-authored-by: Dylan Baker <[email protected]>

Author: 2 people

test cases/osx/9 global variable ar/libfile.c

@@ -0,0 +1,9 @@
+// Source: https://lists.gnu.org/archive/html/libtool/2002-07/msg00025.html
+
+#include <stdio.h>
+
+extern int l2;
+void l1(void)
+{
+  printf("l1 %d\n", l2);
+}

test cases/osx/9 global variable ar/libfile2.c

@@ -0,0 +1,7 @@
+// Source: https://lists.gnu.org/archive/html/libtool/2002-07/msg00025.html
+
+int l2;
+void l2_func(void)
+{
+  l2 = 77;
+}

test cases/osx/9 global variable ar/meson.build

@@ -0,0 +1,6 @@
+# Source: https://lists.gnu.org/archive/html/libtool/2002-07/msg00025.html
+
+project('global variable test', 'c')
+
+lib = static_library('mylib', 'libfile.c', 'libfile2.c')
+test('global variable', executable('prog', 'prog.c', link_with: lib))

test cases/osx/9 global variable ar/nativefile.ini

@@ -0,0 +1,2 @@
+[binaries]
+ar = 'ar'

test cases/osx/9 global variable ar/prog.c

@@ -0,0 +1,7 @@
+// Source: https://lists.gnu.org/archive/html/libtool/2002-07/msg00025.html
+
+extern void l1(void);
+int main(void)
+{
+  l1();
+}