Revert "rt: Call the Rust box annihilator; stop calling the cycle collector" due to crashes

This reverts commit bb0ad11.

Author: pcwalton

src/rt/rust.cpp

@@ -72,8 +72,6 @@ command_line_args : public kernel_owned<command_line_args>
 // FIXME (#2670): This belongs somewhere else
 int check_claims = 0;
 
-void* global_crate_map = NULL;
-
 /**
    The runtime entrypoint. The (C ABI) main function generated by rustc calls
    `rust_start`, providing the address of the Rust ABI main function, the
@@ -88,8 +86,6 @@ rust_start(uintptr_t main_fn, int argc, char **argv, void* crate_map) {
     // line as well.
     rust_env *env = load_env();
 
-    global_crate_map = crate_map;
-
     update_gc_metadata(crate_map);
 
     update_log_settings(crate_map, env->logspec);

src/rt/rust_globals.h

@@ -101,6 +101,4 @@ static size_t const BUF_BYTES = 2048;
 // (writing), a port (reading) or a task (waiting).
 struct rust_cond { };
 
-extern void* global_crate_map;
-
 #endif /* RUST_GLOBALS_H */

src/rt/rust_task.cpp

@@ -9,8 +9,6 @@
 #include "rust_cc.h"
 #include "rust_env.h"
 #include "rust_port.h"
-#include "rust_globals.h"
-#include "rust_crate_map.h"
 
 // Tasks
 rust_task::rust_task(rust_sched_loop *sched_loop, rust_task_state state,
@@ -127,9 +125,18 @@ cleanup_task(cleanup_args *args) {
         main_task_failed_without_spawning = true;
     }
 
-    // Call the box annihilator.
-    cratemap* map = reinterpret_cast<cratemap*>(global_crate_map);
-    task->call_on_rust_stack(NULL, const_cast<void*>(map->annihilate_fn()));
+    // FIXME (#2676): For performance we should do the annihilator
+    // instead of the cycle collector even under normal termination, but
+    // since that would hide memory management errors (like not derefing
+    // boxes), it needs to be disableable in debug builds.
+    if (threw_exception) {
+        // FIXME (#2676): When the annihilator is more powerful and
+        // successfully runs resource destructors, etc. we can get rid
+        // of this cc
+        cc::do_cc(task);
+        annihilate_boxes(task);
+    }
+    cc::do_final_cc(task);
 
     task->die();