Add test for shadowing inline assembly instruction

test/libsolidity/SolidityParser.cpp

@@ -1479,6 +1479,19 @@ BOOST_AUTO_TEST_CASE(function_type_state_variable)
 	BOOST_CHECK(successParse(text));
 }
 
+BOOST_AUTO_TEST_CASE(inline_assembly_shadowed_instruction)
+{
+	char const* text = R"(
+		contract A {
+			function f() {
+				assembly {
+					let gas := 1
+				}
+			}
+		}
+	)";
+	CHECK_PARSE_ERROR(text, "Cannot shadow instructions with variable declaration.");
+}
 
 BOOST_AUTO_TEST_SUITE_END()