Initialize default `context` in `heap_allocator_other.odin`

base/runtime/heap_allocator_other.odin

@@ -3,13 +3,16 @@
 package runtime
 
 _heap_alloc :: proc "contextless" (size: int, zero_memory := true) -> rawptr {
+	context = default_context()
 	unimplemented("base:runtime 'heap_alloc' procedure is not supported on this platform")
 }
 
 _heap_resize :: proc "contextless" (ptr: rawptr, new_size: int) -> rawptr {
+	context = default_context()
 	unimplemented("base:runtime 'heap_resize' procedure is not supported on this platform")
 }
 
 _heap_free :: proc "contextless" (ptr: rawptr) {
+	context = default_context()
 	unimplemented("base:runtime 'heap_free' procedure is not supported on this platform")
 }