[asan] Use dynamic allocator space address on Android/AArch64.

[eugenis]

Summary

We need one library to support all of 39, 42 and 48 bit VMAs, and
there is no common address that works for all of them.

compiler-rt/trunk/lib/asan/asan_allocator.h

 const uptr kAllocatorSpace = ~(uptr)0;
 const uptr kAllocatorSize  =  0x40000000000ULL;  // 4T.
 typedef DefaultSizeClassMap SizeClassMap;
 # elif defined(__powerpc64__)
 const uptr kAllocatorSpace = ~(uptr)0;
 const uptr kAllocatorSize  =  0x20000000000ULL;  // 2T.
 typedef DefaultSizeClassMap SizeClassMap;
 # elif defined(__aarch64__) && SANITIZER_ANDROID
-const uptr kAllocatorSpace =  0x3000000000ULL;
+// Android needs to support 39, 42 and 48 bit VMA.
+const uptr kAllocatorSpace =  ~(uptr)0;
 const uptr kAllocatorSize  =  0x2000000000ULL;  // 128G.
 typedef VeryCompactSizeClassMap SizeClassMap;
 # elif defined(__aarch64__)
 // AArch64/SANITIZER_CAN_USER_ALLOCATOR64 is only for 42-bit VMA
 // so no need to different values for different VMA.
 const uptr kAllocatorSpace =  0x10000000000ULL;
 const uptr kAllocatorSize  =  0x10000000000ULL;  // 3T.
 typedef DefaultSizeClassMap SizeClassMap;