When you add a condition to a StringSwitch::Case, you also have
to change the function to call Cases instead of Case. Not a big deal
but it's always slightly annoying.
This patch renames Cases Case so that we have single overloaded
function
Cases(<one or more strings>, <result>)
instead of two functions
Case(<string>, <result>) and Cases(<two or more strings>, <result>)
I'll delete Cases after updating LLVM subproject's source.