[riscv64] Fix uncorrectly branch

Change-Id: Ic73b5414e62de76a3d4d604c52686c273d9a1b44
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2970813
Commit-Queue: Yahan Lu <yahan@iscas.ac.cn>
Commit-Queue: Ji Qiu <qiuji@iscas.ac.cn>
Auto-Submit: Yahan Lu <yahan@iscas.ac.cn>
Reviewed-by: Ji Qiu <qiuji@iscas.ac.cn>
Cr-Commit-Position: refs/heads/master@{#75238}

src/codegen/riscv64/macro-assembler-riscv64.cc

@@ -4640,7 +4640,7 @@ void TurboAssembler::LoadCodeObjectEntry(Register destination,
 
   if (options().isolate_independent_code) {
     DCHECK(root_array_available());
-    Label if_code_is_off_heap, no_builtin_index, out;
+    Label if_code_is_off_heap, out;
 
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
@@ -4653,11 +4653,10 @@ void TurboAssembler::LoadCodeObjectEntry(Register destination,
     // trampoline.  Otherwise, just call the Code object as always.
 
     Lw(scratch, FieldMemOperand(code_object, Code::kFlagsOffset));
-    Branch(&if_code_is_off_heap, ne, scratch,
-           Operand(Code::IsOffHeapTrampoline::kMask));
+    And(scratch, scratch, Operand(Code::IsOffHeapTrampoline::kMask));
+    Branch(&if_code_is_off_heap, ne, scratch, Operand(zero_reg));
     // Not an off-heap trampoline object, the entry point is at
     // Code::raw_instruction_start().
-    bind(&no_builtin_index);
     Add64(destination, code_object, Code::kHeaderSize - kHeapObjectTag);
     Branch(&out);
 
@@ -4665,9 +4664,6 @@ void TurboAssembler::LoadCodeObjectEntry(Register destination,
     // table.
     bind(&if_code_is_off_heap);
     Lw(scratch, FieldMemOperand(code_object, Code::kBuiltinIndexOffset));
-    // TODO(RISCV): https://github.com/v8-riscv/v8/issues/373
-    Branch(&no_builtin_index, eq, scratch,
-           Operand(static_cast<int>(Builtin::kNoBuiltinId)));
     slli(destination, scratch, kSystemPointerSizeLog2);
     Add64(destination, destination, kRootRegister);
     Ld(destination,