Port member initialization from constructor to declaration (C++11)

Using `clang-tidy`'s `modernize-use-default-member-init` check and
manual review of the changes, and some extra manual changes that
`clang-tidy` failed to do.

Also went manually through all of `core` to find occurrences that
`clang-tidy` couldn't handle, especially all initializations done
in a constructor without using initializer lists.

3 files changed, 20 insertions, 32 deletions

diff --git a/servers/audio/effects/audio_effect_record.h b/servers/audio/effects/audio_effect_record.h
index 09101033be..68d968c04b 100644
--- a/servers/audio/effects/audio_effect_record.h
+++ b/servers/audio/effects/audio_effect_record.h
@@ -49,7 +49,7 @@ class AudioEffectRecordInstance : public AudioEffectInstance {
 
 	bool is_recording;
 	Thread *io_thread;
-	bool thread_active;
+	bool thread_active = false;
 
 	Vector<AudioFrame> ring_buffer;
 	Vector<float> recording_data;
@@ -71,8 +71,7 @@ public:
 	virtual void process(const AudioFrame *p_src_frames, AudioFrame *p_dst_frames, int p_frame_count);
 	virtual bool process_silence() const;
 
-	AudioEffectRecordInstance() :
-			thread_active(false) {}
+	AudioEffectRecordInstance() {}
 	~AudioEffectRecordInstance();
 };
 
diff --git a/servers/audio/effects/reverb.cpp b/servers/audio/effects/reverb.cpp
index ea2174f1d4..02565f4516 100644
--- a/servers/audio/effects/reverb.cpp
+++ b/servers/audio/effects/reverb.cpp
@@ -31,7 +31,9 @@
 // Author: Juan Linietsky <reduzio@gmail.com>, (C) 2006
 
 #include "reverb.h"
+
 #include "core/math/math_funcs.h"
+
 #include <math.h>
 
 const float Reverb::comb_tunings[MAX_COMBS] = {
@@ -338,11 +340,8 @@ Reverb::Reverb() {
 	params.predelay = 150;
 	params.predelay_fb = 0.4;
 	params.hpf = 0;
-	hpf_h1 = 0;
-	hpf_h2 = 0;
 
 	input_buffer = memnew_arr(float, INPUT_BUFFER_MAX_SIZE);
-	echo_buffer = nullptr;
 
 	configure_buffers();
 	update_parameters();
diff --git a/servers/audio/effects/reverb.h b/servers/audio/effects/reverb.h
index 92e4aed435..ed8c824148 100644
--- a/servers/audio/effects/reverb.h
+++ b/servers/audio/effects/reverb.h
@@ -58,44 +58,34 @@ private:
 
 	struct Comb {
 
-		int size;
-		float *buffer;
-		float feedback;
-		float damp; //lowpass
-		float damp_h; //history
-		int pos;
-		int extra_spread_frames;
-
-		Comb() {
-			size = 0;
-			buffer = 0;
-			feedback = 0;
-			damp_h = 0;
-			pos = 0;
-		}
+		int size = 0;
+		float *buffer = nullptr;
+		float feedback = 0;
+		float damp = 0; //lowpass
+		float damp_h = 0; //history
+		int pos = 0;
+		int extra_spread_frames = 0;
+
+		Comb() {}
 	};
 
 	struct AllPass {
 
-		int size;
-		float *buffer;
-		int pos;
-		int extra_spread_frames;
-		AllPass() {
-			size = 0;
-			buffer = 0;
-			pos = 0;
-		}
+		int size = 0;
+		float *buffer = nullptr;
+		int pos = 0;
+		int extra_spread_frames = 0;
+		AllPass() {}
 	};
 
 	Comb comb[MAX_COMBS];
 	AllPass allpass[MAX_ALLPASS];
 	float *input_buffer;
-	float *echo_buffer;
+	float *echo_buffer = nullptr;
 	int echo_buffer_size;
 	int echo_buffer_pos;
 
-	float hpf_h1, hpf_h2;
+	float hpf_h1, hpf_h2 = 0;
 
 	struct Parameters {