[V8][Wasm] Removes references to finally in wasm.

The initial support for low level exception handling in Wasm will not
support finally blocks. This decision is taken for both simplicity (
handling finallys is not straightforward if we want try blocks to yield
values), and lack of good use case (clang++ does not need them.) They
may be added in the future once we understand the implications of
having them.

BUG=

Review-Url: https://codereview.chromium.org/2336303002
Cr-Commit-Position: refs/heads/master@{#39393}

src/wasm/wasm-opcodes.h

@@ -56,11 +56,8 @@ const WasmCodePosition kNoCodePosition = -1;
   V(Return, 0x09, _)              \
   V(Unreachable, 0x0a, _)         \
   V(Throw, 0xfa, _)               \
-  V(TryCatch, 0xfb, _)            \
-  V(TryCatchFinally, 0xfc, _)     \
-  V(TryFinally, 0xfd, _)          \
+  V(Try, 0xfb, _)                 \
   V(Catch, 0xfe, _)               \
-  V(Finally, 0xff, _)             \
   V(End, 0x0F, _)
 
 // Constants, locals, globals, and calls.

test/unittests/wasm/ast-decoder-unittest.cc

@@ -2003,73 +2003,17 @@ TEST_F(AstDecoderTest, Throw) {
 #define WASM_CATCH(local) kExprCatch, static_cast<byte>(local)
 TEST_F(AstDecoderTest, TryCatch) {
   FLAG_wasm_eh_prototype = true;
-  EXPECT_VERIFIES_INLINE(sigs.v_i(), kExprTryCatch, WASM_CATCH(0), kExprEnd);
+  EXPECT_VERIFIES_INLINE(sigs.v_i(), kExprTry, WASM_CATCH(0), kExprEnd);
 
   // Missing catch.
-  EXPECT_FAILURE_INLINE(sigs.v_v(), kExprTryCatch, kExprEnd);
+  EXPECT_FAILURE_INLINE(sigs.v_v(), kExprTry, kExprEnd);
 
   // Missing end.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatch, WASM_CATCH(0));
+  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTry, WASM_CATCH(0));
 
   // Double catch.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatch, WASM_CATCH(0), WASM_CATCH(0),
+  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTry, WASM_CATCH(0), WASM_CATCH(0),
                         kExprEnd);
-
-  // Unexpected finally.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatch, WASM_CATCH(0), kExprFinally,
-                        kExprEnd);
-}
-
-TEST_F(AstDecoderTest, TryFinally) {
-  FLAG_wasm_eh_prototype = true;
-  EXPECT_VERIFIES_INLINE(sigs.v_v(), kExprTryFinally, kExprFinally, kExprEnd);
-
-  // Mising finally.
-  EXPECT_FAILURE_INLINE(sigs.v_v(), kExprTryFinally, kExprEnd);
-
-  // Missing end.
-  EXPECT_FAILURE_INLINE(sigs.v_v(), kExprTryFinally, kExprFinally);
-
-  // Double finally.
-  EXPECT_FAILURE_INLINE(sigs.v_v(), kExprTryFinally, kExprFinally, kExprFinally,
-                        kExprEnd);
-
-  // Unexpected catch.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatch, WASM_CATCH(0), kExprFinally,
-                        kExprEnd);
-}
-
-TEST_F(AstDecoderTest, TryCatchFinally) {
-  FLAG_wasm_eh_prototype = true;
-  EXPECT_VERIFIES_INLINE(sigs.v_i(), kExprTryCatchFinally, WASM_CATCH(0),
-                         kExprFinally, kExprEnd);
-
-  // Missing catch.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatchFinally, kExprFinally,
-                        kExprEnd);
-
-  // Double catch.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatchFinally, WASM_CATCH(0),
-                        WASM_CATCH(0), kExprFinally, kExprEnd);
-
-  // Missing finally.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatchFinally, WASM_CATCH(0),
-                        kExprEnd);
-
-  // Double finally.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatchFinally, WASM_CATCH(0),
-                        kExprFinally, kExprFinally, kExprEnd);
-
-  // Finally before catch.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatchFinally, kExprFinally,
-                        WASM_CATCH(0), kExprEnd);
-
-  // Missing both try and finally.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatchFinally, kExprEnd);
-
-  // Missing end.
-  EXPECT_FAILURE_INLINE(sigs.v_i(), kExprTryCatchFinally, WASM_CATCH(0),
-                        kExprFinally);
 }
 
 class WasmOpcodeLengthTest : public TestWithZone {
@@ -2100,11 +2044,8 @@ TEST_F(WasmOpcodeLengthTest, Statements) {
   EXPECT_LENGTH(3, kExprBr);
   EXPECT_LENGTH(3, kExprBrIf);
   EXPECT_LENGTH(1, kExprThrow);
-  EXPECT_LENGTH(1, kExprTryCatch);
-  EXPECT_LENGTH(1, kExprTryFinally);
-  EXPECT_LENGTH(1, kExprTryCatchFinally);
+  EXPECT_LENGTH(1, kExprTry);
   EXPECT_LENGTH(2, kExprCatch);
-  EXPECT_LENGTH(1, kExprFinally);
 }
 
 TEST_F(WasmOpcodeLengthTest, MiscExpressions) {
@@ -2348,11 +2289,8 @@ TEST_F(WasmOpcodeArityTest, Control) {
   }
 
   EXPECT_ARITY(0, kExprThrow);
-  EXPECT_ARITY(0, kExprTryCatch);
-  EXPECT_ARITY(0, kExprTryFinally);
-  EXPECT_ARITY(0, kExprTryCatchFinally);
+  EXPECT_ARITY(0, kExprTry);
   EXPECT_ARITY(1, kExprCatch, 2);
-  EXPECT_ARITY(0, kExprFinally);
 }
 
 TEST_F(WasmOpcodeArityTest, Misc) {