[MIPS] Rewrite MIPS crtbegin* as C files.

This updates the MIPS arch to be much more in
sync with the commit Nick Kralevich made last
June; see 9d40326830c2bd407427889c554adeb915ee6b4a.

    Rewrite
     crtbegin.S        -> crtbegin.c
     crtbegin_so.S     -> crtbegin_so.c
     __dso_handle.S    -> __dso_handle.c
     __dso_handle_so.S -> __dso_handle_so.c
     atexit.S          -> atexit.c

Previously __do_global_dtors_aux was in the tasks
__FINI_ARRAY__ linked with crtbegin.S and it now being
removed as there is no need to call a destructor just
before terminating a process.

Shared libraries, on the other hand, are linked with
crtbegin_so.c and have a hidden destructor declared
to allow the bionic linker to call __on_dlclose().

Change-Id: Ieb4da5199b54573de05743990e309db381a11cb8
Signed-off-by: Pete Delaney  <piet.delaney@imgtec.com>
Signed-off-by: Chao-Ying Fu  <chao-ying.fu@imgtec.com>
Signed-off-by: Chris Dearman <chris.dearman@imgtec.com>
diff --git a/libc/arch-mips/bionic/crtbegin.c b/libc/arch-mips/bionic/crtbegin.c
new file mode 100644
index 0000000..d3a3401
--- /dev/null
+++ b/libc/arch-mips/bionic/crtbegin.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#include "../../bionic/libc_init_common.h"
+#include <stddef.h>
+#include <stdint.h>
+
+__attribute__ ((section (".preinit_array")))
+void (*__PREINIT_ARRAY__)(void) = (void (*)(void)) -1;
+
+__attribute__ ((section (".init_array")))
+void (*__INIT_ARRAY__)(void) = (void (*)(void)) -1;
+
+__attribute__ ((section (".fini_array")))
+void (*__FINI_ARRAY__)(void) = (void (*)(void)) -1;
+
+
+__LIBC_HIDDEN__  void do_mips_start(void *raw_args) {
+  structors_array_t array;
+  array.preinit_array = &__PREINIT_ARRAY__;
+  array.init_array = &__INIT_ARRAY__;
+  array.fini_array = &__FINI_ARRAY__;
+
+  __libc_init(raw_args, NULL, &main, &array);
+}
+
+/*
+ * This function prepares the return address with a branch-and-link
+ * instruction (bal) and then uses a .cpload to compute the Global
+ * Offset Table (GOT) pointer ($gp). The $gp is then used to load
+ * the address of _do_start() into $t9 just before calling it.
+ * Terminating the stack with a NULL return address.
+ */
+__asm__ (
+"       .set push                   \n"
+"                                   \n"
+"       .text                       \n"
+"       .align  4                   \n"
+"       .type __start,@function     \n"
+"       .globl __start              \n"
+"       .globl  _start              \n"
+"                                   \n"
+"       .ent    __start             \n"
+"__start:                           \n"
+" _start:                           \n"
+"       .frame   $sp,32,$ra         \n"
+"       .mask   0x80000000,-4       \n"
+"                                   \n"
+"       .set noreorder              \n"
+"       bal     1f                  \n"
+"       nop                         \n"
+"1:                                 \n"
+"       .cpload $ra                 \n"
+"       .set reorder                \n"
+"                                   \n"
+"       move    $a0, $sp            \n"
+"       addiu   $sp, $sp, (-32)     \n"
+"       sw      $0, 28($sp)         \n"
+"       la      $t9, do_mips_start  \n"
+"       jalr    $t9                 \n"
+"                                   \n"
+"2:     b       2b                  \n"
+"       .end    __start             \n"
+"                                   \n"
+"       .set pop                    \n"
+);
+
+#include "__dso_handle.h"
+#include "atexit.h"