IG5 native C decompiler integration

IG5's C ABI and mapped-image adapter are project-owned integration code under
the project's CC BY-NC-SA 4.0 license. The analysis implementation linked into
this artifact is the upstream Ghidra native decompiler, not a replacement or
redistribution of a commercial Reverse engine.

Upstream: NationalSecurityAgency/ghidra
Source baseline: 8b6bbb857accdfa20dc5b2f5dea471178c2e9fbc
Upstream license: Apache License, Version 2.0; upstream copyright/license headers
are preserved without alteration. See the installed Ghidra-LICENSE.txt and the
source tree's Ghidra/Features/Decompiler/src/decompile/zlib/README.txt for zlib.

This build excludes GNU BFD and its GPL linkage, the Java communication shell,
the console main program, and the Java analysis framework. It links SLEIGH,
the native decompiler action pipeline, and the C-language printer.

The C ABI provides bounded image, flow-instruction, image-read and text-output
budgets. It does not provide a preemptive optimizer time limit. Always invoke
it inside an owned isolated worker with an external execution deadline. A
successful function result is real native decompilation; no claim of universal
function discovery, high-level semantic equivalence, complete OS analysis, or
mobile-host execution is made.
