Codegen mul by negative power of two with a shift and negate. This implements test/Regression/CodeGen/PowerPC/mul-neg-power-2.ll, producing:
Codegen mul by negative power of two with a shift and negate.
This implements test/Regression/CodeGen/PowerPC/mul-neg-power-2.ll,
producing:

_foo:
        slwi r2, r3, 1
        subfic r3, r2, 63
        blr

instead of:

_foo:
        mulli r2, r3, -2
        addi r3, r2, 63
        blr


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@24106 91177308-0d34-0410-b5e6-96231b3b80d8

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