Fix input/output cli flags for new core.os package

src/file/file.odin

@@ -0,0 +1,36 @@
+package file
+
+import "core:fmt"
+import "core:os"
+
+// TODO:
+// - list files in directory
+//   - get relative path
+// - read file contents
+// - write file contents
+
+Asset :: struct {
+	path: string,
+	size: i64,
+	data: []u8,
+}
+
+read :: proc(f: ^os.File) -> Asset {
+	path := os.name(f)
+
+	size, err := os.file_size(f)
+	if err != nil {
+		fmt.eprintln("error: failed to get file size:", err)
+		os.exit(1)
+	}
+
+	data := make([]u8, size)
+
+	n, read_err := os.read_full(f, data)
+	if read_err != nil {
+		fmt.eprintln("read failed:", read_err, "got", n, "of", size, "bytes")
+		os.exit(1)
+	}
+
+	return Asset{path = path, size = size, data = data}
+}