Treat common symbol as undefined for --no-define-common

When --no-define-common is used to build shared library, treat common
symbol as undefined so that common symbols that are referenced from a
shared library to be assigned addresses only in the main program.  This
eliminates the unused duplicate space in the shared library, and also
prevents any possible confusion over resolving to the wrong duplicate
when there are many dynamic modules with specialized search paths for
runtime symbol resolution.

--no-define-common is only allowed when building a shared library.

bfd/

	PR ld/21903:
	* elflink.c (elf_link_add_object_symbols): Treat common symbol
	as undefined for --no-define-common.

include/

	PR ld/21903:
	* bfdlink.h (bfd_link_info): Add inhibit_common_definition.

ld/

	PR ld/21903:
	* ld.h (command_line): Remove inhibit_common_definition.
	* ldgram.y: Replace command_line.inhibit_common_definition with
	link_info.inhibit_common_definition.
	* ldlang.c (lang_common): Likewise.
	* lexsup.c (parse_args): Likewise.
	* ldmain.c (main): Only allow --no-define-common with -shared.
	* testsuite/ld-elf/pr21903.s: New file.
	* testsuite/ld-elf/pr21903a.d: Likewise.
	* testsuite/ld-elf/pr21903b.d: Likewise.
	* testsuite/ld-elf/pr21903c.d: Likewise.
	* testsuite/ld-elf/pr21903d.d: Likewise.
	* testsuite/ld-elf/pr21903e.d: Likewise.

1 files changed, 0 insertions, 3 deletions

diff --git a/ld/ld.h b/ld/ld.h
index 162e156..c6fa124 100644
--- a/ld/ld.h
+++ b/ld/ld.h
@@ -132,9 +132,6 @@ typedef struct
   /* 1 => assign space to common symbols even if `relocatable_output'.  */
   bfd_boolean force_common_definition;
 
-  /* 1 => do not assign addresses to common symbols.  */
-  bfd_boolean inhibit_common_definition;
-
   /* If TRUE, build MIPS embedded PIC relocation tables in the output
      file.  */
   bfd_boolean embedded_relocs;