No correctness fixes here, just minor qoi fixes:
* Don't insert a branch to the switch instruction after the call, just
make it a single block.
* Insert the new alloca instructions in the entry block of the original
function instead of having them execute dynamically
* Don't make the default edge of the switch instruction go back to the switch.
The loop extractor shouldn't create new loops!
* Give meaningful names to the alloca slots and the reload instructions
* Some minor code simplifications
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12402
91177308-0d34-0410-b5e6-
96231b3b80d8