Add ddc resources to the sdk build

This installs DDC's dart_sdk.js, etc., under:
  dart-sdk/lib/_internal/dev_compiler/

Fixes #27001

[email protected]

Review URL: https://codereview.chromium.org/2416783005 .

Author: vsmenon

tools/create_sdk.py

@@ -47,6 +47,7 @@
 # ......_internal/
 #.........spec.sum
 #.........strong.sum
+#.........dev_compiler/
 # ......analysis_server/
 # ......analyzer/
 # ......async/
@@ -169,6 +170,9 @@ def CopyAnalysisSummaries(snapshots, lib):
   copyfile(join(snapshots, 'strong.sum'),
            join(lib, '_internal', 'strong.sum'))
 
+def CopyDevCompilerSdk(home, lib):
+  copytree(join(home, 'pkg', 'dev_compiler', 'lib', 'js'),
+           join(lib, '_internal', 'dev_compiler'))
 
 def Main():
   # Pull in all of the gypi files which will be munged into the sdk.
@@ -304,6 +308,7 @@ def Main():
   CopyDartdocResources(HOME, SDK_tmp)
   CopyAnalyzerSources(HOME, LIB)
   CopyAnalysisSummaries(SNAPSHOT, LIB)
+  CopyDevCompilerSdk(HOME, LIB)
 
   # Write the 'version' file
   version = utils.GetVersion()