make libtask compatible with Julia 1.6 (#2176)

* make libtask compatible with Julia 1.6

* remove deleted fields in task_t

L/Libtask/build_tarballs.jl

@@ -2,10 +2,10 @@
 # `julia build_tarballs.jl --help` to see a usage message.
 using BinaryBuilder, Pkg
 
-julia_version = v"1.5.1"
+julia_version = v"1.6.0"
 
 name = "Libtask"
-version = v"0.4.2"
+version = v"0.4.3"
 
 # Collection of sources required to build Libtask
 sources = [

L/Libtask/bundled/task.c

@@ -35,20 +35,28 @@ jl_task_t *jl_clone_task(jl_task_t *t)
     newt->gcstack = NULL;
     JL_GC_PUSH1(&newt);
 
+#if JULIA_VERSION_MAJOR == 1 && JULIA_VERSION_MINOR < 6
     newt->state = t->state;
+    newt->exception = jl_nothing;
+    newt->backtrace = jl_nothing;
+#else
+    // newt->next = jl_nothing;
+    newt->_state = t->_state;
+    newt->_isexception = t->_isexception;
+    newt->prio = t->prio;
+    newt->excstack = NULL; // t->excstack;
+#endif
+
     newt->start = t->start;
     newt->tls = jl_nothing;
     newt->logstate = ptls->current_task->logstate;
     newt->result = jl_nothing;
     newt->donenotify = jl_nothing;
-    newt->exception = jl_nothing;
-    newt->backtrace = jl_nothing;
     newt->eh = t->eh;
     newt->gcstack = t->gcstack;
     newt->tid = t->tid;          // TODO: need testing
     newt->started = t->started;  // TODO: need testing
 
-
     newt->copy_stack = t->copy_stack;
     memcpy((void*)newt->ctx.uc_mcontext, (void*)t->ctx.uc_mcontext, sizeof(jl_jmp_buf));
     newt->queue = t->queue;