gas: Fix some x86_64 testcases for Solaris not using R_X86_64_PLT32 [PR25732]

gas: Fix some x86_64 testcases for Solaris not using R_X86_64_PLT32 [PR25732]

As reported in PR gas/25732, some testcases currently FAIL on
Solaris/x86:

FAIL: x86-64 branch 2
FAIL: x86-64 branch 3
FAIL: x86-64 MPX branch
FAIL: x86-64 branch with BND prefix
FAIL: x86-64 jump

Since https://sourceware.org/ml/binutils/2019-03/msg00163.html, gas
doesn't emit R_X86_64_PLT32 as branch marker on Solaris.  Since the
testsuite lacks a way to preprocess dump files, adjusted copies of the
affected dumps are now used on Solaris.  Unfortunately, those dumps
weren't adapted when the original testcases were changed or other
testcases started to differ between non-Solaris and Solaris targets.

The following patch fixes that, re-syncing the affected dump files or
creating new Solaris-specific ones.

Tested on i386-pc-solaris2.11, x86_64-pc-solaris2.11,
x86_64-pc-linux-gnu, and i686-pc-linux-gnu.

	PR gas/25732
	* testsuite/gas/i386/solaris/x86-64-branch-2.d: New file.
	* testsuite/gas/i386/solaris/x86-64-branch-3.d: New file.
	* testsuite/gas/i386/solaris/x86-64-jump.d: Incorporate changes to
	testsuite/gas/i386/x86-64-jump.d.
	* gas/testsuite/gas/i386/solaris/x86-64-mpx-branch-1.d:
	Incorporate changes to
	gas/testsuite/gas/i386/x86-64-mpx-branch-1.d.
	* testsuite/gas/i386/solaris/x86-64-mpx-branch-2.d : Incorporate
	changes to testsuite/gas/i386/x86-64-mpx-branch-2.d.
	* testsuite/gas/i386/x86-64-branch-2.d: Skip on *-*-solaris*.
	* testsuite/gas/i386/x86-64-branch-3.d: Likewise.