_locore_start needs to set up an 8-byte aligned stack
Sadly, during removal of special early-boot stacks
(027eb01d0ff8f66be55208b58ecd7cb2b7b27714) the stack passed into mlsetup
lost its 8-byte aligned-ness.

*** 121,137 ****
          orr     r0, #0x1000
          orr     r0, #0x400000
          mcr     p15, 0, r0, c1, c0, 0
  
          /*
!          * mlsetup() takes the struct regs as an argument. main doesn't take any
!          * and should never return. After the push below, we should have a
!          * 8-byte aligned stack pointer. This is why we subtracted four earlier
!          * on if we were 8-byte aligned.
           */
          mov     r9,#0
!         push    { r9 }
          mov     r0, sp
          bl      mlsetup
          bl      main
          /* NOTREACHED */
          ldr     r0,=__return_from_main
--- 121,142 ----
          orr     r0, #0x1000
          orr     r0, #0x400000
          mcr     p15, 0, r0, c1, c0, 0
  
          /*
!          * mlsetup() takes the struct regs as an argument. main doesn't take
!          * any and should never return. Currently, we have an 8-byte aligned
!          * stack.  We want to push a zero frame pointer to terminate any
!          * stack walking, but that would cause us to end up with only a
!          * 4-byte aligned stack.  So, to keep things nice and correct, we
!          * push a zero value twice - it's similar to a typical function
!          * entry:
!          *      push { r9, lr }
           */
          mov     r9,#0
!         push    { r9 }          /* link register */
!         push    { r9 }          /* frame pointer */
          mov     r0, sp
          bl      mlsetup
          bl      main
          /* NOTREACHED */
          ldr     r0,=__return_from_main