do not create copy relocations when linking to shared libs

Originally committed as revision 11202 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -1737,6 +1737,7 @@ enabled extra_warnings && check_cflags -Winline
 check_ldflags -Wl,--warn-common
 check_ldflags $LDLATEFLAGS
 check_ldflags -Wl,-Bsymbolic
+check_ldflags -Wl,-z,nocopyreloc
 
 if enabled small; then
     check_cflags -Os            # not all compilers support -Os
@@ -1752,12 +1753,9 @@ fi
 
 # PIC flags for shared library objects where they are needed
 if enabled shared; then
-    # LIBOBJFLAGS may have already been set in the OS configuration
-    if test -z "$LIBOBJFLAGS" ; then
-        case "$arch" in
-            x86_64|ia64|alpha|sparc*|power*) LIBOBJFLAGS='$(PIC)' ;;
-        esac
-    fi
+    case "$arch" in
+        x86_64|ia64|alpha|sparc*|power*) add_cflags '\$(PIC)' ;;
+    esac
 fi
 
 if enabled gprof; then