Refresh aarch64-gcc prebuilt.

Changes include:
- Based on GCC 4.8.2
- Add Android specific changes: -D__ANDROID__, -fpic, and
  /system/bin/linker64

Change-Id: Ife9088193be38ef48e8717f911d1604b68f080ae
diff --git a/aarch64-linux-android/lib/ldscripts/aarch64elfb.xsc b/aarch64-linux-android/lib/ldscripts/aarch64elfb.xsc
index 02dafb4..bf1a035 100644
--- a/aarch64-linux-android/lib/ldscripts/aarch64elfb.xsc
+++ b/aarch64-linux-android/lib/ldscripts/aarch64elfb.xsc
@@ -67,8 +67,8 @@
   /* These sections are generated by the Sun/Oracle C++ compiler.  */
   .exception_ranges   : ONLY_IF_RO { *(.exception_ranges
   .exception_ranges*) }
-  /* Adjust the address for the data segment.  We want to align at exactly
-     a page boundary to make life easier for apriori. */
+  /* Adjust the address for the data segment.  For 32 bits we want to align
+  at exactly a page boundary to make life easier for apriori. */
   . = ALIGN(CONSTANT (MAXPAGESIZE)) + (. & (CONSTANT (MAXPAGESIZE) - 1));
   /* Exception handling  */
   .eh_frame       : ONLY_IF_RW { KEEP (*(.eh_frame)) }