Go generator: consolidate CGo import declarations to reduce build time

[Randalphwa]

Problem

The kwxgen Go generator currently emits import "C" in every generated *_gen.go file:

// Code generated by kwxgen. DO NOT EDIT.

package wx

// #include "kwx_classes.h"
import "C"

With 200+ generated files, this means the Go toolchain launches 200+ separate C compiler invocations, each re-parsing the full kwx_classes.h header tree. CGo does not share parsed header state across files in the same package. On a 32-core machine the build is still extremely slow because the C compilation bottleneck dominates.

Expected Behavior

The generator should consolidate all C function declarations into a single generated file (e.g., cgo_glue_gen.go) that contains all the // extern ... declarations and a single import "C". The remaining *_gen.go files would contain only pure Go wrapper functions — no import "C" — and would call helpers/type-casted C pointers from the consolidated glue file.

This is the standard pattern for large CGo packages and reduces C compiler invocations from O(N files) to O(1).

Impact

• On a 32-core Windows machine, go build of the wx package takes several minutes
• Nearly all of that time is redundant header parsing
• After consolidation, incremental and clean builds should be dramatically faster (seconds instead of minutes)