Don't zero r1 on entry to the dynamic linker.

There's no need: __linker_init only takes one argument.

Also remove the arm __CTOR_LIST__; we use .init_array and .fini_array instead
of .ctor and .dtor anyway, and I don't think we've ever supported the latter.

Change-Id: Ifc91a5a90c6aa39d674bf0509a7af2e1ff0beddd

linker/arch/arm/begin.S

@@ -26,20 +26,12 @@
  * SUCH DAMAGE.
  */
 
-	.text
-	.align 4
-	.type _start,#function
-	.globl _start
+#include <private/bionic_asm.h>
 
-_start:
-	mov	r0, sp
-	mov	r1, #0
-	bl	__linker_init
+ENTRY(_start)
+  mov r0, sp
+  bl __linker_init
 
-	/* linker init returns the _entry address in the main image */
-	mov	pc, r0
-
-	.section .ctors, "wa"
-	.globl __CTOR_LIST__
-__CTOR_LIST__:
-	.long -1
+  /* linker init returns the _entry address in the main image */
+  mov pc, r0
+END(_start)

linker/arch/arm64/begin.S

@@ -30,8 +30,7 @@
 
 ENTRY(_start)
   mov x0, sp
-  mov x1, xzr
-  bl  __linker_init
+  bl __linker_init
 
   /* linker init returns the _entry address in the main image */
   br x0

linker/arch/x86_64/begin.S

@@ -29,7 +29,6 @@
 #include <private/bionic_asm.h>
 
 ENTRY(_start)
-  /* Pass elfdata to __linker_init. */
   mov %rsp, %rdi
   call __linker_init