JS: move BufferedReader into the reading loop when reading shader source code
JS: move BufferedReader into the reading loop when reading shader source code

Avoids a dead store to null at the end and scopes the reader more tightly.

Signed-off-by: Harvey Harrison <eadbd6b462bf3c97df0300a934c12bc2e5d1fe51@gmail.com>

jaamsim/jaamsim,jaamsim/jaamsim,jaamsim/jaamsim,jaamsim/jaamsim