PowerPC disassembler: Don't emit trailing spaces

When an instruction has operands, the PowerPC disassembler prints
spaces after the opcode so as to line up operands.  If the operands
are all optional and all default value, then no operands are printed,
leaving trailing spaces.  This patch fixes that.

opcodes/
	* ppc-dis.c (print_insn_powerpc): Delay printing spaces after
	opcode until first operand is output.
gas/
	* testsuite/gas/ppc/476.d: Remove trailing spaces.
	* testsuite/gas/ppc/a2.d: Likewise.
	* testsuite/gas/ppc/booke.d: Likewise.
	* testsuite/gas/ppc/booke_xcoff.d: Likewise.
	* testsuite/gas/ppc/e500.d: Likewise.
	* testsuite/gas/ppc/e500mc.d: Likewise.
	* testsuite/gas/ppc/e6500.d: Likewise.
	* testsuite/gas/ppc/htm.d: Likewise.
	* testsuite/gas/ppc/power6.d: Likewise.
	* testsuite/gas/ppc/power8.d: Likewise.
	* testsuite/gas/ppc/power9.d: Likewise.
	* testsuite/gas/ppc/vle.d: Likewise.
ld/
	* testsuite/ld-powerpc/tlsexe32.d: Remove trailing spaces.
	* testsuite/ld-powerpc/tlsopt5.d: Likewise.
	* testsuite/ld-powerpc/tlsopt5_32.d: Likewise.