Fix libraries displacement if they change whether they were prelinked.
* solib-svr4.c (LM_ADDR_CHECK): Set L_ADDR even if the DYNAMIC pointer
does not match. Comment why.
gdb/testsuite/
* gdb.base/break-interp-lib.c (v, vptr): New variables.
* gdb.base/break-interp.exp (test_attach): New comment.
* gdb.base/break-interp-lib.c: Include unistd.h, assert.h and stdio.h.
(libfunc): New parameter action. Implement also selectable "sleep".
* gdb.base/break-interp-main.c: Include assert.h.
(libfunc): New parameter action.
(main): New parameters argc and argv. Assert argc. Pass argv.
* gdb.base/break-interp.exp (test_core): Pass the "segv" argument.
(test_attach): New proc.
(test_ld): Pass new "segv" exec parameter. Call also test_attach.
* lib/gdb.exp (core_find): New parameter arg. Pass it to $binfile.
* gdb.base/break-interp-main.c, gdb.base/break-interp-lib.c: New.
* gdb.base/break-interp.exp: Exit on skip_shlib_tests. Change $srcfile.
New variables $binfile_lib and $srcfile_lib. Call get_compiler_info
and gdb_compile_shlib. Use new -Wl compiler options.
(dl bt, main bt): New tests.
