rs6000.md (movdi splitter): Sign extend more efficiently.

rs6000.md (movdi splitter): Sign extend more efficiently.

	* rs6000.md (movdi splitter): Sign extend more efficiently.
	* rs6000.c (reg_or_arith_cint_operand): Redefine 64-bit constant
	to "long long" valid on 32-bit and 64-bit hosts.
	(logical_operand): Cast trunc_int_for_mode rturn value.
	(rs6000_emit_move): Shift macro to encapsulate variable.
	(rs6000_va_start): Use HOST_WIDE_INT_PRINT_DEC.
	(rs6000_emit_{prologue,epilogue}): EH regno is unsigned but
	plus_constant requires signed argument.

From-SVN: r42111