Use naive definition of `memset` for !windows

core/runtime/procs_everything_else.odin

@@ -3,28 +3,13 @@ package runtime
 
 @(link_name="memset")
 memset :: proc "c" (ptr: rawptr, val: i32, len: int) -> rawptr {
-	when false {
-		b := byte(val);
+	b := byte(val);
 
-		p_start := uintptr(ptr);
-		p_end := p + uintptr(max(len, 0));
-		for p := p_start; p < p_end; p += 1 {
-			(^byte)(p)^ = b;
-		}
-
-		return ptr;
-	} else {
-		foreign _ {
-			when size_of(rawptr) == 8 {
-				@(link_name="llvm.memset.p0i8.i64")
-				llvm_memset :: proc(dst: rawptr, val: byte, len: int, align: i32, is_volatile: bool) ---;
-			} else {
-				@(link_name="llvm.memset.p0i8.i32")
-				llvm_memset :: proc(dst: rawptr, val: byte, len: int, align: i32, is_volatile: bool) ---;
-			}
-
-		}
-		llvm_memset(ptr, byte(val), len, 1, false);
-		return ptr;
+	p_start := uintptr(ptr);
+	p_end := p + uintptr(max(len, 0));
+	for p := p_start; p < p_end; p += 1 {
+		(^byte)(p)^ = b;
 	}
+
+	return ptr;
 }