re PR target/26915 (missed sized opt returning -1.0)

re PR target/26915 (missed sized opt returning -1.0)

        PR target/26915
        * config/i386/i386.c (standard_80387_constant_p): Treat -0.0 and -1.0
        as a valid 80387 constant.
        (standard_80387_constant_opcode): Return "#" for -0.0 and -1.0.
        * config/i386/i386.md (unnamed splitter): Split the load of
        constant -0.0 or -1.0  into the load of 0.0 or 1.0, followed
        by negation.

testsuite/ChangeLog:

        PR target/26915
        * gcc.target/i386/387-12.c: New test.
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From-SVN: r118484