[wasm] Add loop assignment analysis.

src/wasm/ast-decoder.h

Index: src/wasm/ast-decoder.h
diff --git a/src/wasm/ast-decoder.h b/src/wasm/ast-decoder.h
index 67aae6096d54c8d283210c4529f3355811e4f177..883b6c14b1c1b036d715a226fa5ae1882cae5aec 100644
--- a/src/wasm/ast-decoder.h
+++ b/src/wasm/ast-decoder.h
@@ -12,6 +12,8 @@
 namespace v8 {
 namespace internal {
 
+class BitVector;  // forward declaration
+
 namespace compiler {  // external declarations from compiler.
 class WasmGraphBuilder;
 }
@@ -106,6 +108,9 @@ enum ReadUnsignedLEB128ErrorCode { kNoError, kInvalidLEB128, kMissingLEB128 };
 ReadUnsignedLEB128ErrorCode ReadUnsignedLEB128Operand(const byte*, const byte*,
                                                       int*, uint32_t*);
 
+BitVector* AnalyzeLoopAssignmentForTesting(Zone* zone, FunctionEnv* env,
+                                           const byte* start, const byte* end);
+
 // Computes the length of the opcode at the given address.
 int OpcodeLength(const byte* pc);