swift234

Look for EOF in addition to whitespace to lex the #endif token

In addition to just a whitespace char, also look ahead to a null
character to lex the #endif token.  This allows the token to be formed
when at the end of a file.

Fix endif-on-end-of-file.swift test file to not end in whitespace.

rdar://problem/21692337

Swift SVN r32224