(float{,uns}sidf2): Rewrite to break the conversion process into several
general insns.
(move_to_float): New insns to move 2 integer regs into a float
register through memory, taking endianess into account.  Make sure
that the floating temporary is a valid address.  Use one temporary for
all floats converted.
(fix_truncdfsi2): Take endianess into account.

From-SVN: r10480