Squashed 'external/imgui/imgui/' content from commit d4ddc46e7

git-subtree-dir: external/imgui/imgui
git-subtree-split: d4ddc46e7773e9a9b68f965d007968f35ca4e09a

backends/vulkan/glsl_shader.vert

@@ -0,0 +1,25 @@
+#version 450 core
+layout(location = 0) in vec2 aPos;
+layout(location = 1) in vec2 aUV;
+layout(location = 2) in vec4 aColor;
+
+layout(push_constant) uniform uPushConstant {
+    vec2 uScale;
+    vec2 uTranslate;
+} pc;
+
+out gl_PerVertex {
+    vec4 gl_Position;
+};
+
+layout(location = 0) out struct {
+    vec4 Color;
+    vec2 UV;
+} Out;
+
+void main()
+{
+    Out.Color = aColor;
+    Out.UV = aUV;
+    gl_Position = vec4(aPos * pc.uScale + pc.uTranslate, 0, 1);
+}