Make type string buffer 1MiB to (try to) avoid buffer overflow

Author: NHDaly

src/gc-heap-snapshot.cpp

@@ -226,9 +226,9 @@ size_t record_node_to_gc_snapshot(jl_value_t *a) JL_NOTSAFEPOINT {
                 : (size_t)jl_datatype_size(type);
 
             // print full type
-            // TODO: We _definitely_ have types longer than 1024 bytes....
+            // TODO(PR): Is it possible to use a variable size string here, instead??
             ios_t str_;
-            ios_mem(&str_, 1024);
+            ios_mem(&str_, 1048576);  // 1 MiB
             JL_STREAM* str = (JL_STREAM*)&str_;
 
             jl_static_show(str, (jl_value_t*)type);