Add libunwindstack support for Mips and Mips64

This patch requires v3.18 kernel or above, because v3.10 kernel
has a bug (as of 8/1/2017) in the ptrace(GETREGSET) function for mips
and mips64.

Change-Id: I004c1fa190193eebe1c84440b366289122a6bd8a
Signed-off-by: Douglas Leung <douglas.leung@mips.com>
Signed-off-by: Dejan Jovicevic <dejan.jovicevic@mips.com>
diff --git a/libunwindstack/AsmGetRegsMips.S b/libunwindstack/AsmGetRegsMips.S
new file mode 100644
index 0000000..183d0a9
--- /dev/null
+++ b/libunwindstack/AsmGetRegsMips.S
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+  .text
+  .type     AsmGetRegs, %function
+  .globl    AsmGetRegs
+  .ent      AsmGetRegs
+  .balign   16
+AsmGetRegs:
+  .cfi_startproc
+  .cfi_def_cfa $sp, 0
+  .set push
+  .set noreorder
+  .cpload $t9
+  sw   $zero, 0($a0)
+  .set noat
+  sw   $at, 4($a0)
+  .set at
+  sw   $v0, 8($a0)
+  sw   $v1, 12($a0)
+  sw   $a0, 16($a0)
+  sw   $a1, 20($a0)
+  sw   $a2, 24($a0)
+  sw   $a3, 28($a0)
+  sw   $t0, 32($a0)
+  sw   $t1, 36($a0)
+  sw   $t2, 40($a0)
+  sw   $t3, 44($a0)
+  sw   $t4, 48($a0)
+  sw   $t5, 52($a0)
+  sw   $t6, 56($a0)
+  sw   $t7, 60($a0)
+  sw   $s0, 64($a0)
+  sw   $s1, 68($a0)
+  sw   $s2, 72($a0)
+  sw   $s3, 76($a0)
+  sw   $s4, 80($a0)
+  sw   $s5, 84($a0)
+  sw   $s6, 88($a0)
+  sw   $s7, 92($a0)
+  sw   $t8, 96($a0)
+  sw   $t9, 100($a0)
+  sw   $k0, 104($a0)
+  sw   $k1, 108($a0)
+  sw   $gp, 112($a0)
+  sw   $sp, 116($a0)
+  sw   $s8, 120($a0)
+  sw   $ra, 124($a0)
+  jalr $zero, $ra
+  sw   $ra, 128($a0)   // set PC to the calling function
+
+  .set pop
+  .cfi_endproc
+  .size     AsmGetRegs, .-AsmGetRegs
+  .end      AsmGetRegs