[V8][Wasm] Wasm throws.

src/wasm/ast-decoder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/signature.h"
 
 #include "src/bit-vector.h"
 #include "src/flags.h"
 #include "src/handles.h"
 #include "src/zone-containers.h"
@@ skipping 649 matching lines @@
             break;
           case kExprBlock: {
             // The break environment is the outer environment.
             SsaEnv* break_env = ssa_env_;
             PushBlock(break_env);
             SetEnv("block:start", Steal(break_env));
             break;
           }
           case kExprThrow: {
             CHECK_PROTOTYPE_OPCODE(wasm_eh_prototype);
-            Pop(0, kAstI32);
-
-            // TODO(jpp): start exception propagation.
+            Value value = Pop(0, kAstI32);
+            BUILD(Throw, value.node);
             break;
           }
           case kExprTry: {
             CHECK_PROTOTYPE_OPCODE(wasm_eh_prototype);
             SsaEnv* outer_env = ssa_env_;
             SsaEnv* try_env = Steal(outer_env);
             SsaEnv* catch_env = Split(try_env);
             PushTry(outer_env, catch_env);
             SetEnv("try:start", try_env);
             break;
@@ skipping 1149 matching lines @@
 BitVector* AnalyzeLoopAssignmentForTesting(Zone* zone, size_t num_locals,
                                            const byte* start, const byte* end) {
   FunctionBody body = {nullptr, nullptr, nullptr, start, end};
   WasmFullDecoder decoder(zone, nullptr, body);
   return decoder.AnalyzeLoopAssignmentForTesting(start, num_locals);
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8