Add memmove and memset support for wasm

core/runtime/procs.odin

@@ -1,12 +1,39 @@
 package runtime
 
-memset :: proc "c" (ptr: rawptr, val: i32, len: int) -> rawptr {
-	if ptr != nil && len != 0 {
-		b := byte(val)
-		p := ([^]byte)(ptr)
-		for i in 0..<len {
-			p[i] = b
+when ODIN_ARCH == "wasm32" || ODIN_ARCH == "wasm64" {
+	@(link_name="memset")
+	memset :: proc "c" (ptr: rawptr, val: i32, len: int) -> rawptr {
+		if ptr != nil && len != 0 {
+			b := byte(val)
+			p := ([^]byte)(ptr)
+			for i in 0..<len {
+				p[i] = b
+			}
 		}
+		return ptr
+	}
+	
+	@(link_name="memmove")
+	memmove :: proc "c" (dst, src: rawptr, len: int) -> rawptr {
+		if dst != src {
+			d, s := ([^]byte)(dst), ([^]byte)(src)
+			d_end, s_end := d[len:], s[len:]
+			for i := len-1; i >= 0; i -= 1 {
+				d[i] = s[i]
+			}
+		}
+		return dst
+		
+	}
+} else {
+	memset :: proc "c" (ptr: rawptr, val: i32, len: int) -> rawptr {
+		if ptr != nil && len != 0 {
+			b := byte(val)
+			p := ([^]byte)(ptr)
+			for i in 0..<len {
+				p[i] = b
+			}
+		}
+		return ptr
 	}
-	return ptr
 }