syscall: remove ptrace syscall on ppc64

ptrace is available only for 32 bits programs.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/252558

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-5605a0727d3395becba1fbd4447807073984ec13
+99ab98d2ed8fa8a33947c52925f89b344d7cb8ae
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/syscall/libcall_aix.go

@@ -16,9 +16,6 @@ const SYS_EXECVE = 0
 //sys	Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
 //open64at(dirfd _C_int, path *byte, flags _C_int, mode Mode_t) _C_int
 
-//sys	ptrace(request int, id int, addr uintptr, data int, buff uintptr) (val int)
-//ptrace(request _C_int, id int, addr uintptr, data _C_int, buff *byte) _C_int
-
 //sys	ptrace64(request int, id int64, addr int64, data int, buff uintptr) (err error)
 //ptrace64(request _C_int, id int64, addr int64, data _C_int, buff *byte) _C_int
 

libgo/go/syscall/syscall_aix_ppc.go

@@ -8,6 +8,9 @@ package syscall
 
 import "unsafe"
 
+//sys	ptrace(request int, id int, addr uintptr, data int, buff uintptr) (val int)
+//ptrace(request _C_int, id int, addr uintptr, data _C_int, buff *byte) _C_int
+
 // AIX does not define a specific structure but instead uses separate
 // ptrace calls for the different registers.
 type PtraceRegs struct {