Pass tuples unboxed if possible
All tests pass
Specialize more functions
bugfixes
Remove unnessecary pto argument from emit_unbox
Adjust llvmcall for new tuple infrastructure
Some llvmcall bugfixes
Address compiler warnings

Also remove unused PassManager reference
Also remove PM initialization
Handle nothingness correctly
Fix a performance regression

We used to statically evaluate immutable tuples, but now these get picked up to create unboxed constants. This change allows static insertion of any unboxed constants to boxed constants. Fixes a performance regression in parseint.
tpl -> &tpl and don't use return value from unreachable
Allow unboxed storing tupl purebits tuples
remove invalid check from store_unboxed_p
is_stable_expr for tuples
Fix tuples branch for some changes since it was introduced
Tuples branch bug-fixes
Fix a missing JL_GC_POP
Fix ifelse on the tuple branch
Merge some bugfixes from MCJIT branch