Work in the direction of hard float quick ABIs.

Pass a shorty to ArtMethod::Invoke so that register setup can use it.
Document x86-64 ABI.
Add extra debug output for one JNI native method registration fails, namely a
dump of the Class and its dex file's location.
Add hack to get testing of OatMethod's without GC maps working in 64bit.

Change-Id: Ic06b68e18eac33637df2caf5e7e775ff95ae70f3
diff --git a/runtime/arch/mips/quick_entrypoints_mips.S b/runtime/arch/mips/quick_entrypoints_mips.S
index c60bca0..f9a200a 100644
--- a/runtime/arch/mips/quick_entrypoints_mips.S
+++ b/runtime/arch/mips/quick_entrypoints_mips.S
@@ -456,7 +456,7 @@
      *   a2 = size of argument array in bytes
      *   a3 = (managed) thread pointer
      *   [sp + 16] = JValue* result
-     *   [sp + 20] = result type char
+     *   [sp + 20] = shorty
      */
 ENTRY art_quick_invoke_stub
     GENERATE_GLOBAL_POINTER
@@ -502,7 +502,8 @@
     addiu $sp, $sp, 16
     .cfi_adjust_cfa_offset -16
     lw    $t0, 16($sp)          # get result pointer
-    lw    $t1, 20($sp)          # get result type char
+    lw    $t1, 20($sp)          # get shorty
+    lb    $t1, 0($t1)           # get result type char
     li    $t2, 68               # put char 'D' into t2
     beq   $t1, $t2, 1f          # branch if result type char == 'D'
     li    $t3, 70               # put char 'F' into t3