Remove 2 tests

tests/compile-fail/unsupported_get_process_heap.rs

@@ -1,12 +0,0 @@
-//! `GetProcessHeap()` is special on Windows that it's only supported within libstd.
-//! (On Linux and macOS, it's just always unsupported.)
-
-fn main() {
-    extern "system" {
-        fn GetProcessHeap() -> *mut std::ffi::c_void;
-    }
-    unsafe {
-        GetProcessHeap();
-        //~^ ERROR unsupported operation: can't call foreign function: GetProcessHeap
-    }
-}

tests/run-pass/std_only_foreign_function.rs

@@ -1,39 +0,0 @@
-//! Make sure we can call foreign functions that are only allowed within libstd if we are "libstd"
-//! (defining the `start` lang item).
-#![feature(lang_items, rustc_private, core_intrinsics)]
-#![no_std]
-
-use core::{intrinsics, panic::PanicInfo};
-
-#[lang = "eh_personality"]
-fn rust_eh_personality() {}
-
-#[panic_handler]
-fn panic_handler(_: &PanicInfo<'_>) -> ! {
-    intrinsics::abort()
-}
-
-#[lang = "start"]
-fn start(main: fn(), _argc: isize, _argv: *const *const u8) -> isize {
-    main();
-    0
-}
-
-fn main() {
-    #[cfg(unix)]
-    unsafe {
-        extern crate libc;
-        assert_eq!(libc::signal(libc::SIGPIPE, libc::SIG_IGN), 0);
-    }
-    #[cfg(windows)]
-    unsafe {
-        extern "system" {
-            fn GetProcessHeap() -> *mut core::ffi::c_void;
-            fn ExitProcess(code: u32) -> !;
-        }
-        assert_eq!(GetProcessHeap() as usize, 1);
-        // Early exit to avoid the requirement of
-        // `std::sys::windows::thread_local_key::p_thread_callback`.
-        ExitProcess(0);
-    }
-}