Another missing copy connected to Bravely Default II

adds blit_image_helper.ConvertABGR8ToD32F and fragment shader for performing ABGR and BGRA to D32F copies

src/video_core/host_shaders/CMakeLists.txt

@@ -19,6 +19,7 @@ set(SHADER_FILES
     block_linear_unswizzle_2d.comp
     block_linear_unswizzle_3d.comp
     convert_abgr8_to_d24s8.frag
+    convert_abgr8_to_d32f.frag
     convert_d32f_to_abgr8.frag
     convert_d32f_to_bgra8.frag
     convert_d24s8_to_abgr8.frag

src/video_core/host_shaders/convert_abgr8_to_d32f.frag

@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: Copyright 2023 Your Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#version 450
+
+layout(binding = 0) uniform sampler2D color_texture;
+
+void main() {
+    ivec2 coord = ivec2(gl_FragCoord.xy);
+    vec4 color = texelFetch(color_texture, coord, 0).abgr;
+
+    uvec4 bytes = uvec4(color * (exp2(8) - 1.0f)) << uvec4(24, 16, 8, 0);
+    uint depth_unorm = bytes.x | bytes.y | bytes.z | bytes.w;
+
+    float depth_float = uintBitsToFloat(depth_unorm);
+
+    gl_FragDepth = depth_float;
+}