[wasm] Indirect calls without function table cause validation errors.

src/wasm/ast-decoder.cc

Index: src/wasm/ast-decoder.cc
diff --git a/src/wasm/ast-decoder.cc b/src/wasm/ast-decoder.cc
index ea7ddcf52813b5f2b6dcdfd0c2a56403b3ab7c13..a2d0a3f0dea04fc42bdb79dda0fadcd0588ca982 100644
--- a/src/wasm/ast-decoder.cc
+++ b/src/wasm/ast-decoder.cc
@@ -227,6 +227,11 @@ class WasmDecoder : public Decoder {
   }
 
   inline bool Validate(const byte* pc, CallIndirectOperand& operand) {
+    uint32_t table_index = 0;
+    if (!module_->IsValidTable(table_index)) {
+      error("function table has to exist to execute call_indirect");
+      return false;
+    }
     if (Complete(pc, operand)) {
       return true;
     }