move sparc-sol-thread.c back into sol-thread.c.

The routines in sparc-sol-thread used to be SPARC-specific (and
documented as such in the ptrace man page), and therefore hosting them
in a sparc-specific file made sense.  However, newer versions of
Solaris now use those callbacks (Solaris 10 Update 10, apparently),
and thus the note about these callbacks being specific to SPARC
was removed.

So this patch deletes sparc-sol-thread.c and moves the code back
inside sol-thread.c.

gdb/ChangeLog:

        PR tdep/15420:
        * sol-thread.c (ps_lgetxregsize, ps_lgetxregs, ps_lsetxregs):
        New functions, directly copied from sparc-sol-thread.c.
        * sparc-sol-thread.c: Delete.
        * configure.ac: Remove code handling sparc-solaris-thread.c.
        * configure: Regenerate.
PR remote/15455 - QTro remote packet broken

In the function remote_trace_set_readonly_regions in gdb/remote.c, the
local variable 'offset' does not account for "QTro" at the start of
the packet with the result that if there are any read-only regions,
the packet is sent -- but without the "QTro" -- causing the remote
stub to report that the packet is unsupported:

  Sending packet: $:0000000000400200,(...),00000000004560a4#ab...Packet received:

vs the expected:

  Sending packet: $QTro:0000000000400200,(...),00000000004560a4#31...Packet received: OK

We don't see the problem when testing with GDBserver, as that supports
qXfer:trace-frame-info:read, meaning GDBserver never needs to read
from the read-only sections directly itself.  This commit adds a test
that explicitly disables qXfer:trace-frame-info:read.

gdb/
2013-05-10  David Taylor  <dtaylor@emc.com>

	PR remote/15455

	* remote.c (remote_trace_set_readonly_regions): Do not overwrite
	"QTro" at start of packet.

gdb/testsuite/
2013-05-10  Pedro Alves  <palves@redhat.com>

	PR remote/15455

	* gdb.trace/qtro.c: New file.
	* gdb.trace/qtro.exp: New file.