Fix __builtin_memcpy() argument order
Use the correct pointer as an offset for stret-spills
Don't adjust the stack after a stret
ABI.mk's run target only fails if signalled
Use correct pointer for stret return space
Allocate stack space for stret-via-memcpy
Update ABI.mk to pass LDFLAGS and XCCFLAGS to other-cc
Handle idempotent qualifiers correctly
Merge the type_cmp() equal cases for ?: expressions
Reindent tail-switch in ?: type propagation
Tidy and change of ternary expression type propagation

This mainly fixes things like cond ? (struct A)... : 0; checking.
Thus: moved struct-vs-int example into tests.
Move stret tests
Handle empty-struct return
Move int/float register return example to test
Move bitfield-stret example into tests and update
stdlib: implement div_t div(...)