Create/Update assets for version 1.21.4

assets/minecraft/shaders/core/glint.vsh

@@ -0,0 +1,21 @@
+#version 150
+
+#moj_import <minecraft:fog.glsl>
+
+in vec3 Position;
+in vec2 UV0;
+
+uniform mat4 ModelViewMat;
+uniform mat4 ProjMat;
+uniform mat4 TextureMat;
+uniform int FogShape;
+
+out float vertexDistance;
+out vec2 texCoord0;
+
+void main() {
+    gl_Position = ProjMat * ModelViewMat * vec4(Position, 1.0);
+
+    vertexDistance = fog_distance(Position, FogShape);
+    texCoord0 = (TextureMat * vec4(UV0, 0.0, 1.0)).xy;
+}