Fix rustdoc tests on Windows

Author: GuillaumeGomez

src/test/rustdoc/auxiliary/issue-15318.rs

@@ -4,6 +4,31 @@
 #![feature(lang_items)]
 #![no_std]
 
+#[cfg(windows)]
+#[link(name = "vcruntime")]
+extern {}
+
+#[cfg(windows)]
+#[link(name = "ucrt")]
+extern {}
+
+#[cfg(windows)]
+#[no_mangle]
+#[used]
+static _fltused: i32 = 0;
+#[cfg(windows)]
+#[no_mangle]
+#[used]
+static __aullrem: i32 = 0;
+#[cfg(windows)]
+#[no_mangle]
+#[used]
+static __aulldiv: i32 = 0;
+
+#[cfg(windows)]
+#[no_mangle]
+extern "system" fn _DllMainCRTStartup(_: *const u8, _: u32, _: *const u8) -> u32 { 1 }
+
 #[lang = "eh_personality"]
 fn foo() {}
 

src/test/rustdoc/auxiliary/primitive-doc.rs

@@ -1,6 +1,15 @@
 // compile-flags: --crate-type lib --edition 2018
 #![no_core]
 #![feature(no_core)]
+#![feature(lang_items)]
+
+#[cfg(windows)]
+#[no_mangle]
+extern "system" fn _DllMainCRTStartup(_: *const u8, _: u32, _: *const u8) -> u32 { 1 }
+
+#[cfg(windows)]
+#[lang = "sized"]
+trait Sized {}
 
 #[doc(primitive = "usize")]
 /// This is the built-in type `usize`.