Dependency update
asm goto() incorrect label example
Don't do register-use checks when constraining in/outputs
asm() must use temporaries for register operands
asm() prologue and epilogue
out/__asm.h must be included explicitly - reduce compile times
Prevent output to "i" constraints
Remove blocks - generate output exprs post-asm()

We need to generate the output expressions after the asm() inputs
and inlining. At this point we have the outputs in their temporaries,
e.g. "r" in a register, "m" in temporary memory, and we know what
registers have been allocated to meet this.

We can now generate output lvalues without fear of clobbering
anything as the backend takes care of reg spill normally, so we can
assign to the output lvalues easily.
Register transfer/no-clobber example
Update TODO_ASM - "&" constraint and operand modifiers
Register type test ("eax" vs "rax")
Move asm() modifier examples into __asm/
Assign asm() outputs one at a time

This improves code gen - we don't need to spill the temporary lvalues
when storing, since we do a full output store in one go.
strcpy example
Overflow add - example of "+" constraint
Pull out impl_use_callee_save_reg()
BROKEN: __asm() marks used callee-save regs