Allow to set archiver tool ar.

Originally committed as revision 23010 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -199,6 +199,7 @@ Advanced options (experts only):
   --target-exec=CMD        command to run executables on target
   --target-path=DIR        path to view of build directory on target
   --nm=NM                  use nm tool
+  --ar=AR                  use archive tool AR [$ar_default]
   --as=AS                  use assembler AS [$as_default]
   --cc=CC                  use C compiler CC [$cc_default]
   --ld=LD                  use linker LD
@@ -1132,6 +1133,7 @@ PATHS_LIST='
 
 CMDLINE_SET="
     $PATHS_LIST
+    ar
     arch
     as
     build_suffix
@@ -1442,7 +1444,7 @@ mandir_default='${prefix}/share/man'
 shlibdir_default="$libdir_default"
 
 # toolchain
-ar="ar"
+ar_default="ar"
 cc_default="gcc"
 cc_version=\"unknown\"
 host_cc_default="gcc"
@@ -1641,7 +1643,7 @@ fi
 
 set_default arch target_os
 
-ar="${cross_prefix}${ar}"
+ar_default="${cross_prefix}${ar_default}"
 cc_default="${cross_prefix}${cc_default}"
 nm_default="${cross_prefix}${nm_default}"
 ranlib="${cross_prefix}${ranlib}"
@@ -1852,7 +1854,7 @@ test -n "$cc_type" && enable $cc_type || echolog "Unknown C compiler $cc"
 : ${as_default:=$cc}
 : ${dep_cc_default:=$cc}
 : ${ld_default:=$cc}
-set_default as dep_cc ld
+set_default ar as dep_cc ld
 
 test -n "$CC_DEPFLAGS" || CCDEP=$DEPEND_CMD
 test -n "$AS_DEPFLAGS" || ASDEP=$DEPEND_CMD