x11-terms/kitty: filter graphite flags for now

kitty did a workaround, so it probably won't be needed next
version (albeit I'd suggest to stop using these flags).

Considered backporting the workaround, but think will just filter
after all.

Note I haven't been able to reproduce myself, but haven't tried
much (not looked at debug, X vs wayland, gcc-14 vs 15 and such,
would rather not spend time on this).

Closes: https://bugs.gentoo.org/954894
Signed-off-by: Ionen Wolkens <ionen@gentoo.org>

x11-terms/kitty/kitty-0.41.1-r1.ebuild

@@ -4,7 +4,7 @@
 EAPI=8
 
 PYTHON_COMPAT=( python3_{10..13} )
-inherit edo go-env optfeature multiprocessing
+inherit edo flag-o-matic go-env optfeature multiprocessing
 inherit python-single-r1 toolchain-funcs xdg
 
 if [[ ${PV} == 9999 ]]; then
@@ -136,6 +136,10 @@ src_compile() {
 	tc-export CC
 	local -x PKGCONFIG_EXE=$(tc-getPKG_CONFIG)
 
+	# may cause startup performance issues (bug #954894), kitty upstream did
+	# a workaround in the next version but ideally no one should use these
+	filter-flags -fgraphite-identity -floop-block -floop-parallelize-all
+
 	go-env_set_compile_environment
 	local -x GOFLAGS="-p=$(makeopts_jobs) -v -x -buildvcs=false"
 	use ppc64 && [[ $(tc-endian) == big ]] || GOFLAGS+=" -buildmode=pie"