HomePhabricator

Improve the error message for assigning to read-only variables.

Description

Improve the error message for assigning to read-only variables.

Previously, many error messages would simply be "read-only variable is not
assignable" This change provides more information about why the variable is
not assignable, as well as note to where the const is located.

Differential Revision: http://reviews.llvm.org/D4479