overhaul was to introduce the concept of a "connection point"
between two cells to the ".ext" file format so that it becomes
possible to do proper hierarchical R-C extraction. Previously
this information was not kept in the .ext file, making it
impossible for "extresist" to know what sub-net of a net connects
up or down the hierarchy. However, additional changes were made
to the extresist code (in the resis/ directory) to add the
handling of connections up and down the hierarchy, and to make
the code a lot clearer and fix ambiguous variable and subroutine
names.
This commit makes the code (mostly) C99-compatible, enabling to compile
it without the -Wno-error=implicit-function-declaration flag. This
way, Magic becomes usable on arm64 architectures, specifically on Apple
computers with M1/M2 SoC.