[Dart] Expand spelling dictionary for Dart related words

Dart/resources/spelling/dart.dic

@@ -4,8 +4,11 @@ apiref
 asynchrony
 canonicalized
 charcode
+charcodes
+closurized
 codebases
 codelab
+completers
 constness
 consts
 dart2js
@@ -15,37 +18,55 @@ dartbug
 dartdev
 dartdevc
 dartdoc
+dartdocs
 dartffi
 dartfix
 dartfmt
 dartlang
 dartpad
 dartservices
+dds
 dereferenced
+diagnosticable
 documentable
 embedder
+entrypoints
 fasta
 ffigen
+finalizable
+fixnum
+futureor
+goldens
 hashcodes
 indexable
 intl
 intrinsification
+intrinsify
 jsonrpc
 nnbd
 nonnullable
 nullsafety
+overriden
 pana
 pkgs
 polyfilled
+precompilation
 prettyprint
 protos
+pubignore
 pubspec
+pubspecs
+redeclares
 reflectee
 semver
 smis
 specializer
+superconstructor
 tearoff
+tearoffs
 tflite
+treeshaking
 unawaited
 unprefixed
 walkthrough
+yieldable