Add to CPPFLAGS/CFLAGS in template files, don't over-ride them.

src/template/aix

 if test "$GCC" != yes ; then
   case $host_os in
     aix3.2.5 | aix4.1*)
-      CFLAGS="-O -qmaxmem=16384 -qsrcmsg"
+      CFLAGS="$CFLAGS -O -qmaxmem=16384 -qsrcmsg"
       ;;
     *)
-      CFLAGS="-O2 -qmaxmem=16384 -qsrcmsg -qlonglong"
+      CFLAGS="$CFLAGS -O2 -qmaxmem=16384 -qsrcmsg -qlonglong"
       ;;
   esac
 fi

src/template/freebsd

 case $host_cpu in
-  alpha*)   CFLAGS="-O";;  # alpha has problems with -O2
+  alpha*)   CFLAGS="$CFLAGS -O";;  # alpha has problems with -O2
 esac

src/template/hpux

-CPPFLAGS="-D_XOPEN_SOURCE_EXTENDED"
+CPPFLAGS="$CPPFLAGS -D_XOPEN_SOURCE_EXTENDED"
 
 if test "$GCC" != yes ; then
   CC="$CC -Ae"
-  CFLAGS="+O2"
+  CFLAGS="$CFLAGS +O2"
 fi
 
 # Pick right test-and-set (TAS) code.  We need out-of-line assembler

src/template/linux

 # Force _GNU_SOURCE on; plperl is broken with Perl 5.8.0 otherwise
-CPPFLAGS="-D_GNU_SOURCE"
+CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE"

src/template/osf

 if test "$GCC" != yes ; then
   CC="$CC -std"
-  CFLAGS="-O -ieee"
+  CFLAGS="$CFLAGS -O -ieee"
 fi

src/template/solaris

 if test "$GCC" != yes ; then
   CC="$CC -Xa"			# relaxed ISO C mode
-  CFLAGS="-O -v"		# -v is like gcc -Wall
+  CFLAGS="$CFLAGS -O -v"		# -v is like gcc -Wall
 fi
 
 # Pick right test-and-set (TAS) code.  We need out-of-line assembler

src/template/univel

-CFLAGS="-v -O -K i486,host,inline,loop_unroll -Dsvr4"
+CFLAGS="$CFLAGS -v -O -K i486,host,inline,loop_unroll -Dsvr4"
 LIBS="-lc89"

src/template/unixware

@@ -13,9 +13,9 @@ void g(void){
 __EOF__
 
   if $CC -c -O -Kinline conftest.c >conftest.err 2>&1; then
-    CFLAGS="-O -Kinline"
+    CFLAGS="$CFLAGS -O -Kinline"
   else
-    CFLAGS="-O -Kinline,no_host"
+    CFLAGS="$CFLAGS -O -Kinline,no_host"
   fi
   rm -f conftest.*