Fix syntax highlighting of soft keywords

Author: allanrenucci

compiler/src/dotty/tools/dotc/printing/SyntaxHighlighting.scala

@@ -53,6 +53,7 @@ object SyntaxHighlighting {
         val start = scanner.offset
         val token = scanner.token
         val name = scanner.name
+        val isSoftModifier = scanner.isSoftModifierInModifierPosition
         scanner.nextToken()
         val end = scanner.lastOffset
 
@@ -67,10 +68,7 @@ object SyntaxHighlighting {
             // we don't highlight it, hence the `-1`
             highlightRange(start, end - 1, LiteralColor)
 
-          case _ if alphaKeywords.contains(token) =>
-            highlightRange(start, end, KeywordColor)
-
-          case IDENTIFIER if scanner.isSoftModifierInModifierPosition =>
+          case _ if alphaKeywords.contains(token) || isSoftModifier =>
             highlightRange(start, end, KeywordColor)
 
           case IDENTIFIER if name == nme.??? =>

compiler/test/dotty/tools/dotc/printing/SyntaxHighlightingTests.scala

@@ -125,5 +125,8 @@ class SyntaxHighlightingTests extends DottyTest {
     test("inline def foo = 1", "<K|inline> <K|def> <V|foo> = <L|1>")
     test("@inline def foo = 1", "<T|@inline> <K|def> <V|foo> = <L|1>")
     test("class inline", "<K|class> <T|inline>")
+    test("val inline = 2", "<K|val> <V|inline> = <L|2>")
+    test("def inline = 2", "<K|def> <V|inline> = <L|2>")
+    test("def foo(inline: Int) = 2", "<K|def> <V|foo>(<V|inline>: <T|Int>) = <L|2>")
   }
 }