sys/ptrace.h: add PTRACE_GET_RSEQ_CONFIGURATION from linux v5.13

see

  linux commit 90f093fa8ea48e5d991332cee160b761423d55c1
  rseq, ptrace: Add PTRACE_GET_RSEQ_CONFIGURATION request

the struct type got __ prefix to follow existing practice.

include/sys/ptrace.h

@@ -42,6 +42,7 @@ extern "C" {
 #define PTRACE_SECCOMP_GET_FILTER 0x420c
 #define PTRACE_SECCOMP_GET_METADATA 0x420d
 #define PTRACE_GET_SYSCALL_INFO 0x420e
+#define PTRACE_GET_RSEQ_CONFIGURATION	0x420f
 
 #define PT_READ_I PTRACE_PEEKTEXT
 #define PT_READ_D PTRACE_PEEKDATA
@@ -130,6 +131,14 @@ struct __ptrace_syscall_info {
 	};
 };
 
+struct __ptrace_rseq_configuration {
+	uint64_t rseq_abi_pointer;
+	uint32_t rseq_abi_size;
+	uint32_t signature;
+	uint32_t flags;
+	uint32_t pad;
+};
+
 long ptrace(int, ...);
 
 #ifdef __cplusplus