Add missing #elifdef, #elifndef directives to C/C++ highlights (#45672)

Haojian Wu created

Release Notes:

- Add missing #elifdef, #elifndef directives to C/C++ highlights.

Change summary

crates/languages/src/c/highlights.scm   | 2 ++
crates/languages/src/cpp/highlights.scm | 2 ++
2 files changed, 4 insertions(+)

Detailed changes