Add check for pre-AVX2 gcc versions on x86

c_check

@@ -229,6 +229,16 @@ $architecture = zarch  if ($data =~ /ARCH_ZARCH/);
 $binformat    = bin32;
 $binformat    = bin64  if ($data =~ /BINARY_64/);
 
+
+if ($compiler eq "GCC" &&( ($architecture eq "x86") || ($architecture eq "x86_64"))) {
+$no_avx2 = 0;
+$no_fma = 0;
+$data = `$compiler_name -dumpversion`;
+if ($data <= 4.6) {
+$no_avx2 = 1;
+$no_fma = 1;
+}
+}
 $no_avx512= 0;
 if (($architecture eq "x86") || ($architecture eq "x86_64")) {
     eval "use File::Temp qw(tempfile)";
@@ -368,6 +378,8 @@ print MAKEFILE "CEXTRALIB=$linker_L $linker_l $linker_a\n";
 print MAKEFILE "HAVE_MSA=1\n" if $have_msa eq 1;
 print MAKEFILE "MSA_FLAGS=$msa_flags\n" if $have_msa eq 1;
 print MAKEFILE "NO_AVX512=1\n" if $no_avx512 eq 1;
+print MAKEFILE "NO_AVX2=1\n" if $no_avx2 eq 1;
+print MAKEFILE "NO_FMA=1\n" if $no_fma eq 1;
 
 $os           =~ tr/[a-z]/[A-Z]/;
 $architecture =~ tr/[a-z]/[A-Z]/;