Improved skslc optimizer, particularly around vectors.

BUG=skia:

Change-Id: Idb364d9198f2ff84aad1eb68e236fb45ec1c86b7
Reviewed-on: https://skia-review.googlesource.com/8000
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
diff --git a/src/sksl/ir/SkSLForStatement.h b/src/sksl/ir/SkSLForStatement.h
index b72c26b..ca3e6cf 100644
--- a/src/sksl/ir/SkSLForStatement.h
+++ b/src/sksl/ir/SkSLForStatement.h
@@ -48,10 +48,10 @@
     // it's important to keep fSymbols defined first (and thus destroyed last) because destroying
     // the other fields can update symbol reference counts
     const std::shared_ptr<SymbolTable> fSymbols;
-    const std::unique_ptr<Statement> fInitializer;
+    std::unique_ptr<Statement> fInitializer;
     std::unique_ptr<Expression> fTest;
     std::unique_ptr<Expression> fNext;
-    const std::unique_ptr<Statement> fStatement;
+    std::unique_ptr<Statement> fStatement;
 
     typedef Statement INHERITED;
 };