Reintroduce Math_INF and Math_NAN defines

(cherry picked from commit 6a21f76c4dda8cc63510d77f34c8067e40944974)

include/godot_cpp/core/math_defs.hpp

@@ -44,6 +44,8 @@ namespace godot {
 #define Math_TAU 6.2831853071795864769252867666
 #define Math_PI 3.1415926535897932384626433833
 #define Math_E 2.7182818284590452353602874714
+#define Math_INF INFINITY
+#define Math_NAN NAN
 
 #ifdef DEBUG_ENABLED
 #define MATH_CHECKS