Reduce debug info when not compiling at (debug 3)
Reduce debug info when not compiling at (debug 3)

This reduces variable lifetimes to their last use, instead of their
entire scope. Compile times are slightly faster and generated code is
slightly better, at the expense of debugability.

rvedam/Mezzano,froggey/Mezzano,rvedam/Mezzano,froggey/Mezzano