implement type legalization promotion support for SMULO and UMULO, giving  ARM (and other 32-bit-only) targets support for i8 and i16 overflow  multiplies.  The generated code isn't great, but this at least fixes CodeGen/Generic/overflow.ll when running on ARM hosts.
implement type legalization promotion support for SMULO and UMULO, giving 
ARM (and other 32-bit-only) targets support for i8 and i16 overflow 
multiplies.  The generated code isn't great, but this at least fixes
CodeGen/Generic/overflow.ll when running on ARM hosts.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@122221 91177308-0d34-0410-b5e6-96231b3b80d8

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