crtbegin: eliminate duplicate code

crtbegin_dynamic and crtbegin_static are essentially identical,
minus a few trivial differences (comments and whitespace).

Eliminate duplicates.

Change-Id: Ic9fae6bc9695004974493b53bfc07cd3bb904480
diff --git a/libc/arch-arm/bionic/crtbegin.S b/libc/arch-arm/bionic/crtbegin.S
new file mode 100644
index 0000000..8843204
--- /dev/null
+++ b/libc/arch-arm/bionic/crtbegin.S
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2008 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
+	.align 4
+	.type _start,#function
+	.globl _start
+
+# this is the small startup code that is first run when
+# any executable that is linked with Bionic runs.
+#
+# it's purpose is to call __libc_init with appropriate
+# arguments, which are:
+#
+#    - the address of the raw data block setup by the Linux
+#      kernel ELF loader
+#
+#    - address of an "onexit" function, not used on any
+#      platform supported by Bionic
+#
+#    - address of the "main" function of the program.
+#
+#    - address of the constructor list
+#
+_start:	
+	mov	r0, sp
+	mov	r1, #0
+	ldr	r2, =main
+	adr	r3, 1f
+	ldr	r4, =__libc_init
+	blx	r4
+	mov	r0, #0
+	bx	r0
+
+1:  .long   __PREINIT_ARRAY__
+    .long   __INIT_ARRAY__
+    .long   __FINI_ARRAY__
+    .long   __CTOR_LIST__
+
+	.section .preinit_array, "aw"
+	.globl __PREINIT_ARRAY__
+__PREINIT_ARRAY__:
+	.long -1
+
+	.section .init_array, "aw"
+	.globl __INIT_ARRAY__
+__INIT_ARRAY__:
+	.long -1
+
+	.section .fini_array, "aw"
+	.globl __FINI_ARRAY__
+__FINI_ARRAY__:
+	.long -1
+
+	.section .ctors, "aw"
+	.globl __CTOR_LIST__
+__CTOR_LIST__:
+	.long -1
+
+#include "__dso_handle.S"
+#include "atexit.S"