Incomplete output when source files are large

[legendecas]

Refs: nodejs/node#54994

When the source files are large, the outputs will be incomplete, like env.cc (81K) or node_contextify.cc (69K).

[magic-akari]

The solution is to avoid manually calling process.exit or to call it after stdout is flushed.

However, I now intend not to fix it this way.
Considering the maintenance costs, I'll directly compile the original clangFormat.cpp, which will ensure full support for the original CLI features.