[PATCH] [WIP] Use dynamic alloca for stack variables in ASan.

[Kuba Brecka]

Note that r223799 (Correctly handle complex locations expressions in replaceDbgDeclareForAlloca) by Frederic (@friss) fixes the Obj-C cases. Together with this patch and with -mllvm -asan-stack-dynamic-alloca, I don't see any more missing or invalid debug info.

http://reviews.llvm.org/D6465