Revert "Added constant propagation and better variable liveness tracking to"

This reverts commit f54b07121f81a56145fb118a2e18841fc135717d.

Reason for revert: ASAN failure

Original change's description:
> Added constant propagation and better variable liveness tracking to
> skslc. 
> 
> This allows skslc to track the values of variables with constant
> values across multiple statements and replace variable references with
> constant values where appropriate.
> 
> The improved liveness tracking allows skslc to realize that a
> variable is no longer alive if all references to it have been
> replaced. It is not yet doing much with this information; better
> dead code elimination is coming in a followup change.
> 
> BUG=skia:
> 
> Change-Id: I6bf267d478b769caf0063ac3597dc16bbe618cb4
> Reviewed-on: https://skia-review.googlesource.com/7033
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> 

TBR=egdaniel@google.com,ethannicholas@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Change-Id: Id2e26bce96b27df73948f8b32d3dff2e358ae0d6
Reviewed-on: https://skia-review.googlesource.com/7274
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/src/sksl/ir/SkSLBlock.h b/src/sksl/ir/SkSLBlock.h
index 17970fd561..f975d160a0 100644
--- a/src/sksl/ir/SkSLBlock.h
+++ b/src/sksl/ir/SkSLBlock.h
@@ -20,8 +20,8 @@ struct Block : public Statement {
     Block(Position position, std::vector<std::unique_ptr<Statement>> statements,
           const std::shared_ptr<SymbolTable> symbols)
     : INHERITED(position, kBlock_Kind)
-    , fSymbols(std::move(symbols))
-    , fStatements(std::move(statements)) {}
+    , fStatements(std::move(statements))
+    , fSymbols(std::move(symbols)) {}
 
     SkString description() const override {
         SkString result("{");
@@ -33,10 +33,8 @@ struct Block : public Statement {
         return result;
     }
 
-    // it's important to keep fStatements defined after (and thus destroyed before) fSymbols,
-    // because destroying statements can modify reference counts in symbols
-    const std::shared_ptr<SymbolTable> fSymbols;
     const std::vector<std::unique_ptr<Statement>> fStatements;
+    const std::shared_ptr<SymbolTable> fSymbols;
 
     typedef Statement INHERITED;
 };