[cfe] Move tool/_fasta/ to tool/

Change-Id: I5b7348fb4adb4e7f4039c91d54d712c1eb131ecf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/395002
Reviewed-by: Jens Johansen <jensj@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>

utils/BUILD.gn

@@ -47,7 +47,7 @@ template("aot_compile_using_prebuilt_sdk") {
 }
 
 aot_compile_using_prebuilt_sdk("compile_platform.exe") {
-  entry_point = "$_dart_root/pkg/front_end/tool/_fasta/compile_platform.dart"
+  entry_point = "$_dart_root/pkg/front_end/tool/compile_platform.dart"
   output = "$root_out_dir/compile_platform.exe"
   package_config = "$_dart_root/.dart_tool/package_config.json"
 }

utils/compile_platform.gni

@@ -95,7 +95,7 @@ template("compile_platform") {
       if (defined(invoker.pool)) {
         pool = invoker.pool
       }
-      script = "$_dart_root/pkg/front_end/tool/_fasta/compile_platform.dart"
+      script = "$_dart_root/pkg/front_end/tool/compile_platform.dart"
 
       packages = "$_dart_root/.dart_tool/package_config.json"