[Patch, mach-o/gas] correct a case where stub size is not filled in by GAS.

[Iain Sandoe]

the stub size for well-known-stub sections is not filled in from the  
BFD section translation table, but the other flags *are* when the  
section type is recognized.

This leads to a failure to fill in the stub-size when someone  
specifies a well-known stub section by a hand-written section command.  
(e.g. darwin.S in libffi).

fixed thus:

gas:

	* config/obj-macho.c (obj_mach_o_make_or_get_sect): Always fill in  
stub size
	when provided.  (obj_mach_o_section): Flag that stub-size has been  
provided.

diff --git a/gas/config/obj-macho.c b/gas/config/obj-macho.c
index ba09780..17a21e6 100644
--- a/gas/config/obj-macho.c
+++ b/gas/config/obj-macho.c
@@ -168,6 +168,7 @@ obj_mach_o_get_section_names (char *seg, char *sec,
  #define SECT_TYPE_SPECIFIED 0x0001
  #define SECT_ATTR_SPECIFIED 0x0002
  #define SECT_ALGN_SPECIFIED 0x0004
+#define SECT_STUB_SPECIFIED 0x0008

  static segT
  obj_mach_o_make_or_get_sect (char * segname, char * sectname,
@@ -267,7 +268,6 @@ obj_mach_o_make_or_get_sect (char * segname, char  
* sectname,

        msect->align = secalign;
        msect->flags = sectype | secattr;
-      msect->reserved2 = stub_size;

        if (sectype == BFD_MACH_O_S_ZEROFILL
  	  || sectype == BFD_MACH_O_S_GB_ZEROFILL)
@@ -280,6 +280,10 @@ obj_mach_o_make_or_get_sect (char * segname, char  
* sectname,
  	as_warn (_("Ignoring changed section attributes for %s"), name);
      }

+  if (specified_mask & SECT_STUB_SPECIFIED)
+    /* At present, the stub size is not supplied from the BFD  
tables.  */
+    msect->reserved2 = stub_size;
+
    return sec;
  }

@@ -413,6 +417,7 @@ obj_mach_o_section (int ignore ATTRIBUTE_UNUSED)

  	      input_line_pointer++;
                sizeof_stub = get_absolute_expression ();
+              specified_mask |= SECT_STUB_SPECIFIED;
              }
            else if ((specified_mask & SECT_ATTR_SPECIFIED)
  		   && sectype == BFD_MACH_O_S_SYMBOL_STUBS)