objdump -D of bss sections and -s with -j

There is some inconsistency between the behaviour of objdump -D and
objdump -s, both supposedly operating on all sections by default.
objdump -s ignores bss sections, while objdump -D dissassembles the
zeros.  Fix this by making objdump -D ignore bss sections too.

Furthermore, "objdump -s -j .bss" doesn't dump .bss as it should,
since the user is specifically asking to look at all those zeros.

This change does find some tests that used objdump -D with expected
output in bss-style sections.  I've updated all the msp430 tests that
just wanted to find a non-empty section to look at section headers
instead, making the tests slightly more stringent.  The ppc xcoff and
spu tests are fixed by adding -j options to objdump, which makes the
tests somewhat more lenient.

binutils/
	* objdump.c (disassemble_section): Ignore sections without
	contents, unless overridden by -j.
	(dump_section): Allow -j to override the default of not
	displaying sections without contents.
	* doc/binutils.texi (objdump options): Update -D, -s and -j
	description.
gas/
	* testsuite/gas/ppc/xcoff-tls-32.d: Select wanted objdump
	sections with -j.
	* testsuite/gas/ppc/xcoff-tls-64.d: Likewise.
ld/
	* testsuite/ld-msp430-elf/main-bss-lower.d,
	* testsuite/ld-msp430-elf/main-bss-upper.d,
	* testsuite/ld-msp430-elf/main-const-lower.d,
	* testsuite/ld-msp430-elf/main-const-upper.d,
	* testsuite/ld-msp430-elf/main-text-lower.d,
	* testsuite/ld-msp430-elf/main-text-upper.d,
	* testsuite/ld-msp430-elf/main-var-lower.d,
	* testsuite/ld-msp430-elf/main-var-upper.d: Expect -wh output.
	* testsuite/ld-msp430-elf/msp430-elf.exp: Use objdump -wh
	rather than objdump -D or objdump -d with tests checking for
	non-empty given sections.
	* testsuite/ld-spu/ear.d,
	* testsuite/ld-spu/icache1.d,
	* testsuite/ld-spu/ovl.d,
	* testsuite/ld-spu/ovl2.d: Select wanted objdump sections.

binutils/doc/binutils.texi

@@ -2407,8 +2407,9 @@ used when disassembling.
 
 @item -D
 @itemx --disassemble-all
-Like @option{-d}, but disassemble the contents of all sections, not just
-those expected to contain instructions.
+Like @option{-d}, but disassemble the contents of all non-empty
+non-bss sections, not just those expected to contain instructions.
+@option{-j} may be used to select specific sections.
 
 This option also has a subtle effect on the disassembly of
 instructions in code sections.  When option @option{-d} is in effect
@@ -2502,7 +2503,8 @@ for specification with @option{-b} or @option{-m}.
 @item -j @var{name}
 @itemx --section=@var{name}
 @cindex section information
-Display information only for section @var{name}.
+Display information for section @var{name}.  This option may be
+specified multiple times.
 
 @item -L
 @itemx --process-links
@@ -2775,8 +2777,9 @@ disassembly.
 @itemx --full-contents
 @cindex sections, full contents
 @cindex object file sections
-Display the full contents of any sections requested.  By default all
-non-empty sections are displayed.
+Display the full contents of sections, often used in combination with
+@option{-j} to request specific sections.  By default all non-empty
+non-bss sections are displayed.
 
 @item -S
 @itemx --source

binutils/objdump.c

@@ -3685,15 +3685,18 @@ disassemble_section (bfd *abfd, asection *section, void *inf)
    next_sym
   } loop_until;
 
-  /* Sections that do not contain machine
-     code are not normally disassembled.  */
-  if (! disassemble_all
-      && only_list == NULL
-      && ((section->flags & (SEC_CODE | SEC_HAS_CONTENTS))
-	  != (SEC_CODE | SEC_HAS_CONTENTS)))
-    return;
+  if (only_list == NULL)
+    {
+      /* Sections that do not contain machine
+	 code are not normally disassembled.  */
+      if ((section->flags & SEC_HAS_CONTENTS) == 0)
+	return;
 
-  if (! process_section_p (section))
+      if (! disassemble_all
+	  && (section->flags & SEC_CODE) == 0)
+	return;
+    }
+  else if (!process_section_p (section))
     return;
 
   datasize = bfd_section_size (section);
@@ -4970,10 +4973,12 @@ dump_section (bfd *abfd, asection *section, void *dummy ATTRIBUTE_UNUSED)
   int count;
   int width;
 
-  if (! process_section_p (section))
-    return;
-
-  if ((section->flags & SEC_HAS_CONTENTS) == 0)
+  if (only_list == NULL)
+    {
+      if ((section->flags & SEC_HAS_CONTENTS) == 0)
+	return;
+    }
+  else if (!process_section_p (section))
     return;
 
   if ((datasize = bfd_section_size (section)) == 0)