Remove incorrect special case for Inline purity checks

This special case was added two years ago, quoting from
5428549
"Inlined pure values are pure even if referenced from impure
prefixes (i.e. prefix need not be evaluated)"
This does not match the current semantics for inline where the prefix is
always evaluated.

Author: smarter

src/dotty/tools/dotc/ast/TreeInfo.scala

@@ -328,8 +328,7 @@ trait TypedTreeInfo extends TreeInfo[Type] { self: Trees.Instance[Type] =>
     case Ident(_) =>
       refPurity(tree)
     case Select(qual, _) =>
-      refPurity(tree).min(
-       if (tree.symbol.is(Inline)) Pure else exprPurity(qual))
+      refPurity(tree).min(exprPurity(qual))
     case TypeApply(fn, _) =>
       exprPurity(fn)
 /*