Fix #14740 Hang: createAst, daca package lomiri-location-service (#8551)

Author: chrchr-github

lib/tokenlist.cpp

@@ -740,6 +740,8 @@ static void compileBinOp(Token *&tok, AST_state& state, void (*f)(Token *&tok, A
         binop->astOperand1(state.op.top());
         state.op.pop();
     }
+    if (!state.op.empty() && state.op.top() == binop)
+        throw InternalError(tok, "Syntax Error: Infinite loop when creating AST.", InternalError::AST);
     state.op.push(binop);
 }
 

test/testgarbage.cpp

@@ -1343,6 +1343,8 @@ class TestGarbage : public TestFixture {
                                         "{ return return { | { - name3 1 enum != >= 1 >= ++ { name6 | ; ++}}}}}}}"), UNKNOWN_MACRO);
         ASSERT_THROW_INTERNAL(checkCode("else return % name5 name2 - =name1 return enum | { - name3 1 enum != >= 1 >= ++ { { || "
                                         "{ return return { | { - name3 1 enum != >= 1 >= ++ { { || ; ++}}}}}}}}"), UNKNOWN_MACRO);
+
+        ASSERT_THROW_INTERNAL(checkCode("f(*p, requires(x));"), AST); // #14740
     }
 
     void templateSimplifierCrashes() {