breakpoint.c: fix libc probe scan when no get_longjmp_target exists.

As discussed on the GDB ML[1], libc probes for longjmp were not being
loaded if a custom <arch>_get_longjmp_target function was not
implemented.

This is trivially fixed by moving the 'if (!gdbarch_get_longjmp_target_p
(gdbarch))' down, just bellow libc probe code and above the per-objfile
cache lookup.

While the condition could also be removed altogether with no
side-effects, it is in fact an optimization to avoid searching for
symbols if the arch doesn't provide support for get_longjmp_target().

This has been tested on PPC and PPC64.

[1] https://sourceware.org/ml/gdb/2013-10/msg00191.html

gdb/
2013-11-01  Tiago Stürmer Daitx  <tdaitx@linux.vnet.ibm.com>

        * breakpoint.c (create_longjmp_master_breakpoint): Allow libc
        probe scan even when the arch provides no get_longjmp_target.
gdb.dwarf2/dwzbuildid.exp: Avoid reserved variable name

	* gdb.dwarf2/dwzbuildid.exp: Rename `outdir' variable to
	`debugdir'.
*-*-nacl* layout: Drop requirement that some section have SEC_HAS_CONTENTS set.

bfd/
	* elf-nacl.c (segment_eligible_for_headers): Drop requirement that
	some section have SEC_HAS_CONTENTS set.  It's not set for
	.note.gnu.build-id, and a segment of only read-only SHT_NOBITS
	sections is implausible and not really supportable anyway.
x86_64-*-nacl*: Adjust test cases for PLT nop fix.

ld/testsuite/
	* ld-x86-64/plt-nacl.pd: Update expected disassembly for PLT nop fix.
	* ld-x86-64/tlsdesc-nacl.pd: Likewise.
daily update
gdb.cp/derivation.exp: s/perrro/perror/
Simplify ppc64 code setting toc_off.

Every function has a nominal toc pointer value, even if it isn't used,
so set toc_off for every code section to the value used in that object
file.  The thinking here was that if a code section didn't use the toc
it could use the previous object file's toc pointer value.  It can,
but doing so is only a gain if functions in that section are called
mostly from previous objects sharing the same toc.  We lose if the
functions in question are called mostly from the current object or
following objects, and it's a good bet they will probably mostly be
called from the current object.

	* elf64-ppc.c (ppc64_elf_next_input_section): Always set toc_off
	to value for object file.