src: initialize Environment members in class definition

Initialize primitive members of `Environment` in the class definition
for clarity.

PR-URL: nodejs#25369
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: Matheus Marchini <mat@mmarchini.me>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

src/env.cc

@@ -171,15 +171,9 @@ Environment::Environment(IsolateData* isolate_data,
       immediate_info_(context->GetIsolate()),
       tick_info_(context->GetIsolate()),
       timer_base_(uv_now(isolate_data->event_loop())),
-      printed_error_(false),
-      abort_on_uncaught_exception_(false),
-      emit_env_nonstring_warning_(true),
-      emit_err_name_warning_(true),
-      makecallback_cntr_(0),
       should_abort_on_uncaught_toggle_(isolate_, 1),
       trace_category_state_(isolate_, kTraceCategoryCount),
       stream_base_state_(isolate_, StreamBase::kNumStreamBaseStateFields),
-      http_parser_buffer_(nullptr),
       fs_stats_field_array_(isolate_, kFsStatsBufferLength),
       fs_stats_field_bigint_array_(isolate_, kFsStatsBufferLength),
       context_(context->GetIsolate(), context) {

src/env.h

@@ -945,11 +945,11 @@ class Environment {
   ImmediateInfo immediate_info_;
   TickInfo tick_info_;
   const uint64_t timer_base_;
-  bool printed_error_;
-  bool abort_on_uncaught_exception_;
-  bool emit_env_nonstring_warning_;
-  bool emit_err_name_warning_;
-  size_t makecallback_cntr_;
+  bool printed_error_ = false;
+  bool abort_on_uncaught_exception_ = false;
+  bool emit_env_nonstring_warning_ = true;
+  bool emit_err_name_warning_ = true;
+  size_t makecallback_cntr_ = 0;
   std::vector<double> destroy_async_id_list_;
 
   std::shared_ptr<EnvironmentOptions> options_;
@@ -1004,7 +1004,7 @@ class Environment {
   double* heap_statistics_buffer_ = nullptr;
   double* heap_space_statistics_buffer_ = nullptr;
 
-  char* http_parser_buffer_;
+  char* http_parser_buffer_ = nullptr;
   bool http_parser_buffer_in_use_ = false;
   std::unique_ptr<http2::Http2State> http2_state_;