Added missing linux/user.h structures.

Added equivalents for user_regs_struct and user_struct from linux/user.h for x86 and x86_64.

src/unix/notbsd/linux/other/b32/x86.rs

@@ -19,6 +19,44 @@ s! {
         pub _st: [_libc_fpreg; 8],
         pub status: ::c_ulong,
     }
+    
+    pub struct _libc_state {
+        pub ebx: ::c_long,
+        pub ecx: ::c_long,
+        pub edx: ::c_long,
+        pub esi: ::c_long,
+        pub edi: ::c_long,
+        pub ebp: ::c_long,
+        pub eax: ::c_long,
+        pub xds: ::c_long,
+        pub xes: ::c_long,
+        pub xfs: ::c_long,
+        pub xgs: ::c_long,
+        pub orig_eax: ::c_long,
+        pub eip: ::c_long,
+        pub xcs: ::c_long,
+        pub eflags: u32,
+        pub esp: ::c_long,
+        pub xss: ::c_long,
+    }
+
+    pub struct _libc_user {
+        pub regs: _libc_state,
+        pub u_fpvalid: i32,
+        pub i387: _libc_fpstate,
+        pub u_tsize: u32,
+        pub u_dsize: u32,
+        pub u_ssize: u32,
+        pub start_code: u32,
+        pub start_stack: u32,
+        pub signal: i32,
+        __reserved: i32,
+        pub u_ar0: *mut _libc_state,
+        pub u_fpstate: *mut _libc_fpstate,
+        pub magic: u32,
+        pub u_comm: [c_char; 32],
+        pub u_debugreg: [i32; 8],
+    }
 
     pub struct mcontext_t {
         pub gregs: [greg_t; 19],

src/unix/notbsd/linux/other/b64/x86_64.rs

@@ -78,6 +78,54 @@ s! {
         __private: [u64; 12],
     }
 
+    pub struct _libc_state {
+        pub r15: u64,
+        pub r14: u64,
+        pub r13: u64,
+        pub r12: u64,
+        pub rbp: u64,
+        pub rbx: u64,
+        pub r11: u64,
+        pub r10: u64,
+        pub r9: u64,
+        pub r8: u64,
+        pub rax: u64,
+        pub rcx: u64,
+        pub rdx: u64,
+        pub rsi: u64,
+        pub rdi: u64,
+        pub orig_rax: u64,
+        pub rip: u64,
+        pub cs: u64,
+        pub eflags: u64,
+        pub rsp: u64,
+        pub ss: u64,
+        pub fs_base: u64,
+        pub gs_base: u64,
+        pub ds: u64,
+        pub es: u64,
+        pub fs: u64,
+        pub gs: u64,
+    }
+
+    pub struct _libc_user {
+        pub regs: _libc_state,
+        pub u_fpvalid: ::c_int,
+        pub i387: _libc_fpstate,
+        pub u_tsize: u64,
+        pub u_dsize: u64,
+        pub u_ssize: u64,
+        pub start_code: u64,
+        pub start_stack: u64,
+        pub signal: i64,
+        __reserved: ::c_int,
+        pub u_ar0: *mut _libc_state,
+        pub u_fpstate: *mut _libc_fpstate,
+        pub magic: u64,
+        pub u_comm: [::c_char; 32],
+        pub u_debugreg: [u64; 8],
+    }
+
     pub struct mcontext_t {
         pub gregs: [greg_t; 23],
         pub fpregs: *mut _libc_fpstate,