.gitignore: ignore /compile_commands.json

This is the standard clang JSON Compilation Database file name, as
documented in:

https://clang.llvm.org/docs/JSONCompilationDatabase.html#build-system-integration

FYI the file is used by Language Server Protocol implementations and
other AST tools.

Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: 0-day Robot <robot@bytheb.org>

.gitignore

@@ -42,6 +42,7 @@
 /build-arch-stamp
 /build-indep-stamp
 /compile
+/compile_commands.json
 /config.guess
 /config.h
 /config.h.in