Rollup merge of rust-lang#71023 - mati865:mingw-unwind-linking-cleanup, r=Amanieu

[windows] Add testscase for self-contained executables

Author: Dylan-DPC

src/test/run-make-fulldeps/windows-binary-no-external-deps/Makefile

@@ -0,0 +1,9 @@
+-include ../tools.mk
+
+# only-windows
+
+PATH=$(SYSTEMROOT)/system32
+
+all:
+	$(RUSTC) hello.rs
+	$(TMPDIR)/hello.exe

src/test/run-make-fulldeps/windows-binary-no-external-deps/hello.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello World!");
+}