Implement some GDScript benchmarks (#41)

Co-authored-by: BrunoArmondBraga <abraga3547bruno@gmail.com>

benchmarks/gdscript/for_loop.gd

@@ -0,0 +1,22 @@
+extends Benchmark
+
+const ITERATIONS = 1_000_000
+
+var number := 0
+
+# Benchmark for loop by:
+# 1) Adding a number ITERATIONS times
+# 2) Calling a function ITERATIONS times
+
+func benchmark_for_loop_add() -> void:
+	for i in ITERATIONS:
+		number += 1
+
+
+func function() -> void:
+	pass
+
+
+func benchmark_for_loop_call() -> void:
+	for i in ITERATIONS:
+		function()

benchmarks/gdscript/lambda_performance.gd

@@ -0,0 +1,11 @@
+extends Benchmark
+
+const ITERATIONS = 1_000_000
+
+var lambda = func(): pass
+
+# Benchmark lambda function by calling it ITERATION times
+
+func benchmark_lambda_call() -> void:
+	for i in ITERATIONS:
+		lambda.call()