Allow '//'-style comments in #defines.

            inp();

        }

        String value;

        bool appendToValue = true;

        while (ch != '\n' && ch != EOF) {

            // Check for '//' comments.

            if (appendToValue && ch == '/') {

                inp();

                if (ch == '/') {

                    appendToValue = false;

                } else {

                    value.append('/');

                }

            }

            if (appendToValue && ch != EOF) {

                value.append(ch);

            }

            inp();

        }

        char* pDefn = (char*)mGlobalArena.alloc(value.len() + 1);

// Simple tests of the C preprocessor

#define A (1 + 2)

#define A (4 / 2)

#define B 1 // This is a comment. With a / in it.

int main() {

    return A;

    return A + B;

}