swift234

SILGen: Remove AllocTmp, add AllocVar stack attr
Remove the AllocTmp instruction and represent MaterializeExpr allocations using 'alloc_var stack'/'dealloc_var stack' instructions. Rename Dealloc to DeallocVar, and add an AllocKind attribute to AllocVar and DeallocVar. Update MaterializeExpr SILGen to generate an AllocVar with a DeallocVar cleanup instead of AllocTmp. Tweak SILPrinter's presentation of AllocVar and DeallocVar to be in line with what SIL.rst claims.

Swift SVN r3311