fix: calculate windows dll symbols from prebuilt shared library

crates/linker/src/util.rs

@@ -0,0 +1,23 @@
+use std::time::Duration;
+
+use object::ObjectSymbol;
+
+pub(crate) fn report_timing(label: &str, duration: Duration) {
+    println!("\t{:9.3} ms   {}", duration.as_secs_f64() * 1000.0, label,);
+}
+
+fn is_roc_symbol(sym: &object::Symbol) -> bool {
+    if let Ok(name) = sym.name() {
+        name.trim_start_matches('_').starts_with("roc_")
+    } else {
+        false
+    }
+}
+
+pub(crate) fn is_roc_definition(sym: &object::Symbol) -> bool {
+    sym.is_definition() && is_roc_symbol(sym)
+}
+
+pub(crate) fn is_roc_undefined(sym: &object::Symbol) -> bool {
+    sym.is_undefined() && is_roc_symbol(sym)
+}