64-bit emulator

Patch to allow emulator searches for emulator64-${ARCH} first on
64-bit OS.  If none is found, the original behavior which searchs
for 32-bit emulator-${ARCH} is performed as usual.

64-bit emulator (which still emulates Android built in 32-bit) offers
up to 20% speedup compared to its 32-bit counterpart.

Details:

android/main-emulator.c
 1) search emulator64 based on the OS
 2) dlopen lib64OpenglRender in 64-bit

Makefile.*
 1) Rules to build 64-bit executable emulator64-{x86,arm} and libraries
    emulator64-{libui,libqemu,target-i386,target-arm,libelff,common}
 2) remove -Wa,-32
 3) Changes prebuit toolchain path

android-configure.h
android/build/common.h
 1) no longer force 32-bit build (because now prebuilts/tools/gcc-sdk/gcc
    can now handle 64-bit
 2) set ANDROID_PREBUILTS to correctly locate ccache

android/config/*/config-host.h
 1) Detect HOST_X86_64 and HOST_X86_64/HOST_I386

Misc 64-bit porting clean-up
 1) use %zx to print variable of type size_t in hex
 2) use %zu to print variable of type size_t in dec
 3) Initialize query_parm to NULL
 4) use PRIu64 to replace PDUd64
 5) use PRId64/PRIu64/PRIX64 to print 64-bit
 6) drop PRUx64 because PRIx64 does the same
 7) cast pointer arith to intptr_t before casting to int
 8) fixed 1ULL<<63

Change-Id: Ife62a20063a6ec38d4a9b23977e840af1fce149a
diff --git a/android/console.c b/android/console.c
index ed02db5..07a59d2 100644
--- a/android/console.c
+++ b/android/console.c
@@ -1867,7 +1867,7 @@
         if (q == p)
             break;
 
-        snprintf(temp, sizeof temp, "%.*s", q-p, p);
+        snprintf(temp, sizeof temp, "%.*s", (int)(intptr_t)(q-p), p);
         ret = android_event_from_str( temp, &type, &code, &value );
         if (ret < 0) {
             if (ret == -1) {