Fix usages of mesh simplification functions in float=64 builds

core/io/marshalls.cpp

@@ -1813,3 +1813,24 @@ Error encode_variant(const Variant &p_variant, uint8_t *r_buffer, int &r_len, bo
 
 	return OK;
 }
+
+Vector<float> vector3_to_float32_array(const Vector3 *vecs, size_t count) {
+	// We always allocate a new array, and we don't memcpy.
+	// We also don't consider returning a pointer to the passed vectors when sizeof(real_t) == 4.
+	// One reason is that we could decide to put a 4th component in Vector3 for SIMD/mobile performance,
+	// which would cause trouble with these optimizations.
+	Vector<float> floats;
+	if (count == 0) {
+		return floats;
+	}
+	floats.resize(count * 3);
+	float *floats_w = floats.ptrw();
+	for (size_t i = 0; i < count; ++i) {
+		const Vector3 v = vecs[i];
+		floats_w[0] = v.x;
+		floats_w[1] = v.y;
+		floats_w[2] = v.z;
+		floats_w += 3;
+	}
+	return floats;
+}