Add x86_64-iphonesimulator-gcc target.

macho64 x86_64 with:
- -miphoneos-version-min=5.0
- -isysroot from xcrun --sdk iphonesimulator

Change-Id: I1ba183e16d50c93d48f526e2dc43a7a6040741c5

build/make/configure.sh

@@ -1172,8 +1172,8 @@ EOF
                 enabled icc && ! enabled pic && add_cflags -fno-pic
             ;;
             iphonesimulator)
-                add_asflags -f macho32
-                sim_arch="-arch i386"
+                add_asflags -f macho${bits}
+                enabled x86 && sim_arch="-arch i386" || sim_arch="-arch x86_64"
                 add_cflags  ${sim_arch}
                 add_ldflags ${sim_arch}
            ;;

configure

@@ -137,6 +137,7 @@ all_platforms="${all_platforms} x86_64-darwin10-gcc"
 all_platforms="${all_platforms} x86_64-darwin11-gcc"
 all_platforms="${all_platforms} x86_64-darwin12-gcc"
 all_platforms="${all_platforms} x86_64-darwin13-gcc"
+all_platforms="${all_platforms} x86_64-iphonesimulator-gcc"
 all_platforms="${all_platforms} x86_64-linux-gcc"
 all_platforms="${all_platforms} x86_64-linux-icc"
 all_platforms="${all_platforms} x86_64-solaris-gcc"