Fixing munmap_arena_and_reset issue by reseting allocation_ptr (#1205)

The `allocation_ptr` was the missing variable we needed to reset to
correctly reset the whole semispace GC strategy. This PR fixes issue
#1204 where the `allocation_ptr` kept an old value from a previous GC
iteration that was often higher than the current `oldspace` semispace,
making it impossible to be allocated or to clean the memory using it on
`scan_ptr`

Author: Robertorosmaninho

include/runtime/arena.h

@@ -122,6 +122,7 @@ class arena {
 
     current_addr_ptr = nullptr;
     collection_addr_ptr = nullptr;
+    allocation_ptr = nullptr;
     tripwire = nullptr;
   }
 

runtime/collect/collect.cpp

@@ -347,6 +347,7 @@ void free_all_kore_mem() {
   kore_collect(nullptr, 0, nullptr, true);
   kore_clear();
   youngspace.munmap_arena_and_reset();
+  oldspace.munmap_arena_and_reset();
   alwaysgcspace.munmap_arena_and_reset();
 }
 }