[Impeller] Copy shaders lib to output directory (flutter/engine#37225)

engine/src/flutter/impeller/compiler/BUILD.gn

@@ -94,7 +94,10 @@ impeller_component("impellerc") {
 
   sources = [ "impellerc_main.cc" ]
 
-  deps = [ ":compiler_lib" ]
+  deps = [
+    ":compiler_lib",
+    "shader_lib",
+  ]
 
   metadata = {
     entitlement_file_path = [ "impellerc" ]

engine/src/flutter/impeller/compiler/shader_lib/BUILD.gn

@@ -0,0 +1,10 @@
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+group("shader_lib") {
+  deps = [
+    "./flutter",
+    "./impeller",
+  ]
+}

engine/src/flutter/impeller/compiler/shader_lib/flutter/BUILD.gn

@@ -0,0 +1,8 @@
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+copy("flutter") {
+  sources = [ "runtime_effect.glsl" ]
+  outputs = [ "$root_out_dir/shader_lib/flutter/{{source_file_part}}" ]
+}

engine/src/flutter/impeller/compiler/shader_lib/impeller/BUILD.gn

@@ -0,0 +1,17 @@
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+copy("impeller") {
+  sources = [
+    "blending.glsl",
+    "branching.glsl",
+    "color.glsl",
+    "constants.glsl",
+    "gaussian.glsl",
+    "texture.glsl",
+    "transform.glsl",
+    "types.glsl",
+  ]
+  outputs = [ "$root_out_dir/shader_lib/impeller/{{source_file_part}}" ]
+}