Fix missing types in i686-unknown-linux-musl

src/unix/linux_like/linux/musl/b32/x86/mod.rs

@@ -1,5 +1,6 @@
 pub type c_char = i8;
 pub type wchar_t = i32;
+pub type greg_t = i32;
 
 s! {
     pub struct stat {
@@ -112,6 +113,23 @@ s! {
         pub f_spare: [::c_ulong; 4],
     }
 
+    pub struct _libc_fpreg {
+        pub significand: [u16; 4],
+        pub exponent: u16,
+    }
+
+    pub struct _libc_fpstate {
+        pub cw: ::c_ulong,
+        pub sw: ::c_ulong,
+        pub tag: ::c_ulong,
+        pub ipoff: ::c_ulong,
+        pub cssel: ::c_ulong,
+        pub dataoff: ::c_ulong,
+        pub datasel: ::c_ulong,
+        pub _st: [_libc_fpreg; 8],
+        pub status: ::c_ulong,
+    }
+
     pub struct mcontext_t {
         pub gregs: [greg_t; 19],
         pub fpregs: *mut _libc_fpstate,