Fix memset arguments for MSP430 target.

On MSP430 second argument to memset has i16 type instead of i32.

Author: pftbest

src/mem.rs

@@ -35,6 +35,7 @@ pub unsafe extern "C" fn memmove(dest: *mut u8,
 }
 
 #[no_mangle]
+#[cfg(not(target_pointer_width = "16"))]
 pub unsafe extern "C" fn memset(s: *mut u8, c: i32, n: usize) -> *mut u8 {
     let mut i = 0;
     while i < n {
@@ -44,6 +45,17 @@ pub unsafe extern "C" fn memset(s: *mut u8, c: i32, n: usize) -> *mut u8 {
     s
 }
 
+#[no_mangle]
+#[cfg(target_pointer_width = "16")]
+pub unsafe extern "C" fn memset(s: *mut u8, c: i16, n: usize) -> *mut u8 {
+    let mut i = 0;
+    while i < n {
+        *s.offset(i as isize) = c as u8;
+        i += 1;
+    }
+    s
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
     let mut i = 0;