Auto merge of #71023 - mati865:mingw-unwind-linking-cleanup, r=Amanieu

[windows] Add testscase for self-contained executables and fix pthread linking

Fixes #71061

Author: bors

src/librustc_target/spec/windows_base.rs

@@ -57,9 +57,9 @@ pub fn opts() -> TargetOptions {
             // binaries to be redistributed without the libgcc_s-dw2-1.dll
             // dependency, but unfortunately break unwinding across DLL
             // boundaries when unwinding across FFI boundaries.
-            "-lgcc".to_string(),
             "-lgcc_eh".to_string(),
-            "-lpthread".to_string(),
+            "-l:libpthread.a".to_string(),
+            "-lgcc".to_string(),
             // libpthread depends on libmsvcrt, so we need to link it *again*.
             "-lmsvcrt".to_string(),
             "-lkernel32".to_string(),

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!");
+}