Retry to fix issue 4539 - Refuse assignment to string literal

[9rnsr]

http://d.puremagic.com/issues/show_bug.cgi?id=4539
Fixed #46 dmd-test breaking.

[dnadlinger]

See also: pull request #188.

[9rnsr]

#180 (and the improved #362) is unrelated pull request with this issue.

Current dmd treats string literal as Lvalue, but it is invalid. This patch changes string literal as Rvalue, and passing it to ref parameter will be statically rejected.

[yebblies]

#188 is identical to this one. I missed this one when I created it. In the future please add a link to the pull request on the bug's bugzilla page, and add the patch keywork. I'll close #188.

Also note Don's comment on #188.

[9rnsr]

Updated patch.
Now we can receive string literals by a reference to static array type (e.g. ref const char[N]).
See test4539() in xtest46.d

[yebblies]

I would love to see this in the next release. Bug reports due to this appear quite consistently.