Re-added some changes lost in merges.

libsolidity/AST.cpp

@@ -347,7 +347,7 @@ void ExpressionStatement::checkTypeRequirements()
 void Expression::expectType(Type const& _expectedType)
 {
 	checkTypeRequirements();
-	const Type& type = *getType();
+	Type const& type = *getType();
 	if (!type.isImplicitlyConvertibleTo(_expectedType))
 		BOOST_THROW_EXCEPTION(createTypeError("Type " + type.toString() +
 											  " not implicitly convertible to expected type "

libsolidity/ExpressionCompiler.cpp

@@ -376,8 +376,7 @@ void ExpressionCompiler::appendTypeConversion(Type const& _typeOnStack, Type con
 	else if (_typeOnStack != _targetType)
 	{
 		// All other types should not be convertible to non-equal types.
-		assert(!_typeOnStack.isExplicitlyConvertibleTo(_targetType));
-		assert(false);
+		BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Invalid type conversion requested."));
 	}
 }