Symbol transformation breaks with symbols starting and ending in quotes

[jrappen]

Description of the bug

Symbol transformation breaks with symbols starting and ending in quotes.

Steps to reproduce

1. Define a syntax.
2. Define symbols that start and end in quotes to be transformed.
3. Write syntax tests.

Expected behavior

Syntax tests pass.

Actual behavior

Syntax tests fail.

Compare: sublimehq/Packages#4308

Sublime Text build number

4199