fix OutOfMemoryError

[xuwei-k]

• fix OutOfMemoryError since 4.9.0 #3650

[kitbellew]

@xuwei-k thank you for detecting the problem and proposing a fix.

do you think #3652 will also solve the problem? it uses the fact that Input overall has a cache already, and tokenizers use it:

scalameta/scalameta/inputs/shared/src/main/scala/scala/meta/internal/inputs/InternalInput.scala

Line 13 in eeb1ea6

private[meta] lazy val tokenCache: mutable.Map[Dialect, Tokens] =

scalameta/scalameta/tokenizers/shared/src/main/scala/scala/meta/internal/tokenizers/ScalametaTokenizer.scala

Line 15 in eeb1ea6

def tokenize(): Tokens = {