LLVM r356789 changed the format of textual IR to print nameless
blocks with labels instead of comments with "; <label>". Adjust Swift
tests to match. I also updated the utils/viewcfg script to match.
Switch statements generate at least one anonymous match variable per
case, which consumes both a lot of stack space and an explosion of
range extension depencies due to the way case statements are scoped.
rdar://problem/34326355
Instead of appending a character for each substitution, we now prefix the substitution with the repeat count, e.g.
AbbbbB -> A5B
The same is done for known-type substitutions, e.g.
SiSiSi -> S3i
This significantly shrinks mangled names which contain large lists of the same type, like
func foo(_ x: (Int, Int, Int, Int, Int, Int, Int, Int, Int, Int, Int, Int))
rdar://problem/30707433
Even at -Onone one SILValue can back up more than one local source variable.
This commit changes the list of variable values into a set.
<rdar://problem/28467349>
