[babl] Fix AVX instructions being generated in SSE4.1 code (bug #760292)

[Daniel Sabo <daniels src gnome org>]

commit d8f9a0d48cea1857550aa2b9f030bc1b7d768790
Author: Daniel Sabo <DanielSabo gmail com>
Date:   Thu Jan 7 18:05:44 2016 -0800

    Fix AVX instructions being generated in SSE4.1 code (bug #760292)
    
    The half-float flag got accidentally added to the SSE4.1 flags,
    causing GCC to auto-enable AVX.

 configure.ac |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index e2ab5f7..aed1683 100644
--- a/configure.ac
+++ b/configure.ac
@@ -382,9 +382,11 @@ if test "x$enable_mmx" = xyes; then
         fi
       fi
 
+      CFLAGS="$mmx_save_CFLAGS"
+
       if test "x$enable_f16c" = xyes; then
         BABL_DETECT_CFLAGS(f16c_flag, '-mf16c')
-        SSE4_1_EXTRA_CFLAGS="$SSE_EXTRA_CFLAGS $f16c_flag"
+        F16C_EXTRA_CFLAGS="$SSE_EXTRA_CFLAGS $f16c_flag"
 
         AC_MSG_CHECKING(whether we can compile half-floating point code)
 
@@ -413,6 +415,7 @@ if test "x$enable_mmx" = xyes; then
   AC_SUBST(SSE_EXTRA_CFLAGS)
   AC_SUBST(SSE2_EXTRA_CFLAGS)
   AC_SUBST(SSE4_1_EXTRA_CFLAGS)
+  AC_SUBST(F16C_EXTRA_CFLAGS)
 fi