Maybe link correct msvcrt on debug vs non-debug?

build.rs

@@ -0,0 +1,14 @@
+// Working around https://github.com/purpleprotocol/mimalloc_rust/pull/167 while all the cc, rust,
+// msvc, etc stuff is still being worked on. Kinda unfortunate that we need a build.rs for all
+// targets, but at least it should be quick.
+
+fn main() {
+	if std::env::var("TARGET").is_ok_and(|s| s.contains("windows-msvc"))
+		&& std::env::var("PROFILE").is_ok_and(|p| p == "debug")
+	{
+		// Don't link the default CRT
+		println!("cargo::rustc-link-arg=/nodefaultlib:msvcrt");
+		// Link the debug CRT instead
+		println!("cargo::rustc-link-arg=/defaultlib:msvcrtd");
+	}
+}