pkg: Switch back to building with GCC on Fedora and Arch

After the Eigen migration, GCC seems to produce the faster code again,
but both compilers are very close.

Debian will keep using clang for now, because in bullseye the packaged
clang is one year newer than the packaged GCC.

PKGBUILD

@@ -16,7 +16,7 @@ depends=(
 )
 makedepends=(
 	'meson'
-	'clang'
+	'gcc'
 	'cmake'
 	'microsoft-gsl'
 	'systemd'
@@ -26,10 +26,6 @@ makedepends=(
 build() {
 	cd $startdir
 
-	# Build with clang since it produces faster binaries
-	export CC="clang"
-	export CXX="clang++"
-
 	export CFLAGS="$(echo "$CFLAGS" | sed 's|-O2||g' | sed 's|-mtune=generic||g' | sed 's|-march=x86_64||g')"
 	export CXXFLAGS="$(echo "$CXXFLAGS" | sed 's|-O2||g' | sed 's|-mtune=generic||g' | sed 's|-march=x86_64||g')"
 

iptsd.spec

@@ -1,7 +1,7 @@
 %global debug_package %{nil}
 
 # Build with clang since it produces faster binaries
-%global toolchain clang
+%global toolchain gcc
 
 Name: iptsd
 Version: 1.2.1