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.
option "labels ... cellid" to handle some vendor files where
apparently to get around the 30-character cell name limit, the
actual cellname is encoded on a text layer. Added new cifop
"boundary" (no arguments) for cases where a cell abutment box
is encoded on a GDS layer; this now translates the bounding
box to the FIXED_BBOX property, as is done with the LEF bounding
box. Also corrected the property set function to free existing
property value allocated memory when overwriting a property with
a new value.
Alessandro De Laurenzis
Anton Blanchard
Tim Edwards