11787 Kernel needs to be built with retpolines
11788 Kernel needs to generally use RSB stuffing
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: John Levon <john.levon@joyent.com>

*** 127,137 ****
          swapgs;                         \
          movq    REGOFF_RSI(%rsp), %rsi; \
          movq    REGOFF_RDI(%rsp), %rdi; \
          addq    $REGOFF_RIP, %rsp
  
! #define FAST_INTR_RETURN        call *x86_md_clear; jmp tr_iret_user
  
  #elif defined(__i386)
  
  #define FAST_INTR_PUSH          \
          cld;                    \
--- 127,137 ----
          swapgs;                         \
          movq    REGOFF_RSI(%rsp), %rsi; \
          movq    REGOFF_RDI(%rsp), %rdi; \
          addq    $REGOFF_RIP, %rsp
  
! #define FAST_INTR_RETURN        call x86_md_clear; jmp tr_iret_user
  
  #elif defined(__i386)
  
  #define FAST_INTR_PUSH          \
          cld;                    \