[BUG] Crash.

[MarekKnapek]

Describe the bug
Program terminated with signal: SIGSEGV
Segmentation fault (core dumped)

To Reproduce
Steps to reproduce the behavior:

1. Download source code of cppfront.
2. Compile cppfront.
3. Run cppfront on test.cpp2 file.

Actual result

• Crash.

Expected result

• No crash.
• Maybe nice error message.

Additional context
Test.cpp2 file's content is only 5 bytes long and it is: l:=l*.

[hsutter]

Fixed, thanks!