godot: CPUParticles2D renders wrong with GLES2 on iOS if scene uses NinePatchRect, Panel, Button or ProgressBar

Godot version: Godot 3.1.1-stable official Godot 3.1.2-alpha 8f3fea2058 Godot 3.2-alpha 48d3458f74

OS/device including version: iPad 6th gen / 12.3.1

Issue description: CPUParticles2D renders wrongly when scene has NinePatchRect on GLES2. Here is a table to show if it renders correctly.

CPUParticles2D	GLES2	GLES3
with NinePatchRect	X	O
without NinePatchRect	O	O

on GLES3

on GLES2

Steps to reproduce:

1. Add NinePatchRect and CPUParticles2D
2. run in on iOS device.

Minimal reproduction project: test particle.zip