don't use ::malloc for initializing the global_async_handle in rust_kernel

src/libstd/uv_hl.rs

@@ -17,7 +17,6 @@ native mod rustrt {
     fn rust_uv_get_kernel_global_chan_ptr() -> *libc::uintptr_t;
     fn rust_uv_get_kernel_global_async_handle() -> **libc::c_void;
     fn rust_uv_set_kernel_global_async_handle(handle: *ll::uv_async_t);
-    fn rust_uv_free_kernel_global_async_handle();
 }
 
 #[doc = "

src/rt/rust_kernel.cpp

@@ -27,8 +27,9 @@ rust_kernel::rust_kernel(rust_env *env) :
     // set up storage of pointers needed to
     // access the global loop.
     global_loop_chan = 0;
-    global_async_handle = (void**)::malloc( // FIXME--can't use this->malloc()
-        sizeof(void*));                     // .. what do?
+    int foo = 0;
+    async_handle_stub = (void*)&foo;
+    global_async_handle = &async_handle_stub;
     *global_async_handle = (void*)0;
 
     // Create the single threaded scheduler that will run on the platform's

src/rt/rust_kernel.h

@@ -75,6 +75,7 @@ class rust_kernel {
 
     // Used to communicate with the process-side, global libuv loop
     uintptr_t global_loop_chan;
+    void* async_handle_stub;
     void** global_async_handle;
 
 public:

src/rt/rust_uv.cpp

@@ -454,7 +454,3 @@ extern "C" void
 rust_uv_set_kernel_global_async_handle(uv_async_t* handle) {
     rust_get_current_task()->kernel->set_global_async_handle((void*)handle);
 }
-extern "C" void
-rust_uv_free_kernel_global_async_handle() {
-    free((void*)rust_get_current_task()->kernel->get_global_async_handle());
-}