Accept soft modifiers separated by blank lines

This was handled inconsistently before. An identifier could be classified as
a soft modifier even if followed by newlines but then the modifier parsing code
would not skip the NEWLINES token. Now it does skip.

Author: odersky

compiler/src/dotty/tools/dotc/parsing/Parsers.scala

@@ -2873,7 +2873,7 @@ object Parsers {
           val isAccessMod = accessModifierTokens contains in.token
           val mods1 = addModifier(mods)
           loop(if (isAccessMod) accessQualifierOpt(mods1) else mods1)
-        else if (in.token == NEWLINE && (mods.hasFlags || mods.hasAnnotations)) {
+        else if (in.isNewLine && (mods.hasFlags || mods.hasAnnotations)) {
           in.nextToken()
           loop(mods)
         }

tests/pos/i11712.scala

@@ -0,0 +1,21 @@
+object Test:
+
+  def transparent = println("transparent method called")
+
+  transparent
+  println()
+  inline def f1 = 1
+
+  transparent
+  inline def f2 = 2
+
+  transparent
+  trait T1
+
+  transparent
+
+  inline def f3 = 3
+
+  transparent
+
+  trait T2