No need to check the context for arrow since we are already speculating it based on =>

Fixes #304

Author: sheetalkamat

TypeScript.YAML-tmLanguage

@@ -1441,7 +1441,7 @@ repository:
         '1': { name: storage.modifier.async.ts }
         '2': { name: variable.parameter.ts }
     - name: meta.arrow.ts
-      begin: (?x)(?<=return|throw|yield|await|async|default|[=(\[,:>*])\s*(?=(<([^<>]|\<[^<>]+\>)+>\s*)?\(([^()]|\([^()]*\))*\)(\s*:\s*(.)*)?\s*=>)
+      begin: (?x)\s*(?=(<([^<>]|\<[^<>]+\>)+>\s*)?\(([^()]|\([^()]*\))*\)(\s*:\s*(.)*)?\s*=>)
       end: (?==>)
       patterns:
       - include: '#comment'

TypeScript.tmLanguage

@@ -4069,7 +4069,7 @@
             <key>name</key>
             <string>meta.arrow.ts</string>
             <key>begin</key>
-            <string>(?x)(?&lt;=return|throw|yield|await|async|default|[=(\[,:&gt;*])\s*(?=(&lt;([^&lt;&gt;]|\&lt;[^&lt;&gt;]+\&gt;)+&gt;\s*)?\(([^()]|\([^()]*\))*\)(\s*:\s*(.)*)?\s*=&gt;)</string>
+            <string>(?x)\s*(?=(&lt;([^&lt;&gt;]|\&lt;[^&lt;&gt;]+\&gt;)+&gt;\s*)?\(([^()]|\([^()]*\))*\)(\s*:\s*(.)*)?\s*=&gt;)</string>
             <key>end</key>
             <string>(?==&gt;)</string>
             <key>patterns</key>

TypeScriptReact.tmLanguage

@@ -4051,7 +4051,7 @@
             <key>name</key>
             <string>meta.arrow.tsx</string>
             <key>begin</key>
-            <string>(?x)(?&lt;=return|throw|yield|await|async|default|[=(\[,:&gt;*])\s*(?=(&lt;([^&lt;&gt;]|\&lt;[^&lt;&gt;]+\&gt;)+&gt;\s*)?\(([^()]|\([^()]*\))*\)(\s*:\s*(.)*)?\s*=&gt;)</string>
+            <string>(?x)\s*(?=(&lt;([^&lt;&gt;]|\&lt;[^&lt;&gt;]+\&gt;)+&gt;\s*)?\(([^()]|\([^()]*\))*\)(\s*:\s*(.)*)?\s*=&gt;)</string>
             <key>end</key>
             <string>(?==&gt;)</string>
             <key>patterns</key>

tests/baselines/Issue177.baseline.txt

@@ -8,11 +8,11 @@ Grammar: TypeScript.tmLanguage
 -----------------------------------
 >() => (/s/);
  ^
- source.ts meta.brace.round.ts
+ source.ts meta.arrow.ts meta.parameters.ts punctuation.definition.parameters.begin.ts
   ^
-  source.ts meta.brace.round.ts
+  source.ts meta.arrow.ts meta.parameters.ts punctuation.definition.parameters.end.ts
    ^
-   source.ts
+   source.ts meta.arrow.ts
     ^^
     source.ts meta.arrow.ts storage.type.function.arrow.ts
       ^
@@ -33,11 +33,11 @@ Grammar: TypeScript.tmLanguage
              source.ts
 >() => /s/;
  ^
- source.ts meta.brace.round.ts
+ source.ts meta.arrow.ts meta.parameters.ts punctuation.definition.parameters.begin.ts
   ^
-  source.ts meta.brace.round.ts
+  source.ts meta.arrow.ts meta.parameters.ts punctuation.definition.parameters.end.ts
    ^
-   source.ts
+   source.ts meta.arrow.ts
     ^^
     source.ts meta.arrow.ts storage.type.function.arrow.ts
       ^