mesa: Drop -fno-strict-aliasing.

Improves performance of OglBatch7 by 4.06851% +/- 1.17925% (n=169) on
Haswell, and cuts ~18k of .text:

   text     data      bss      dec      hex  filename
5824627   287816    29384  6141827   5db783  before/i965_dri.so
5806354   287816    29384  6123554   5d7022  after/i965_dri.so

Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
diff --git a/configure.ac b/configure.ac
index 7d1a9bb..aea5890 100644
--- a/configure.ac
+++ b/configure.ac
@@ -300,9 +300,6 @@
     # Restore CFLAGS; VISIBILITY_CFLAGS are added to it where needed.
     CFLAGS=$save_CFLAGS
 
-    # Work around aliasing bugs - developers should comment this out
-    CFLAGS="$CFLAGS -fno-strict-aliasing"
-
     # We don't want floating-point math functions to set errno or trap
     CFLAGS="$CFLAGS -fno-math-errno -fno-trapping-math"
 
@@ -342,9 +339,6 @@
     # Restore CXXFLAGS; VISIBILITY_CXXFLAGS are added to it where needed.
     CXXFLAGS=$save_CXXFLAGS
 
-    # Work around aliasing bugs - developers should comment this out
-    CXXFLAGS="$CXXFLAGS -fno-strict-aliasing"
-
     # We don't want floating-point math functions to set errno or trap
     CXXFLAGS="$CXXFLAGS -fno-math-errno -fno-trapping-math"
 fi