Remove yet more SH4 cruft.

Surely this is the last piece?

Change-Id: I4bd43afb102334ec34d0e14a65c2b319826473d7
diff --git a/libc/arch-sh/syscalls/tgkill.S b/libc/arch-sh/syscalls/tgkill.S
deleted file mode 100644
index 222f836..0000000
--- a/libc/arch-sh/syscalls/tgkill.S
+++ /dev/null
@@ -1,32 +0,0 @@
-/* autogenerated by gensyscalls.py */
-#include <sys/linux-syscalls.h>
-
-    .text
-    .type tgkill, @function
-    .globl tgkill
-    .align 4
-
-tgkill:
-
-    /* invoke trap */
-    mov.l   0f, r3  /* trap num */
-    trapa   #(3 + 0x10)
-
-    /* check return value */
-    cmp/pz  r0
-    bt      __NR_tgkill_end
-
-    /* keep error number */
-    sts.l   pr, @-r15
-    mov.l   1f, r1
-    jsr     @r1
-    mov     r0, r4
-    lds.l   @r15+, pr
-
-__NR_tgkill_end:
-    rts
-    nop
-
-    .align  2
-0:  .long   __NR_tgkill
-1:  .long   __set_syscall_errno