.gitignore: Restore inadvertently deleted file

Restore .gitignore inadvertently deleted by
5eb81a4b40.

Fixes:		5eb81a4b40
Pointy hat to:	cy

.gitignore

@@ -0,0 +1,33 @@
+*.a
+*.core
+*.o
+*.orig
+*.rej
+*.so
+*.sw[nop]
+*~
+_.tinderbox.*
+_.universe-toolchain
+_.amd64.*
+_.arm.*
+_.arm64.*
+_.i386.*
+_.ia64.*
+_.mips.*
+_.pc98.*
+_.powerpc.*
+_.riscv.*
+_.sparc64.*
+_.sun4v.*
+GPATH
+GRTAGS
+GTAGS
+ID
+cscope.files
+cscope.in.out
+cscope.out
+cscope.po.out
+compile_commands.json
+tags
+.clangd
+.ccls-cache