The template parser has a certain interpolation config associated with
it and builds a regular expression each time it needs to extract the
interpolations from an input string. Since the interpolation config is
typically the default of `{{` and `}}`, the regular expression doesn't
have to be recreated each time. Therefore, this commit creates only a
single regular expression instance that is used for the default
configuration.
In a large compilation unit with big templates, computing the regular
expression took circa 275ms. This change reduces this to effectively
zero.
PR Close#34332
940e62ba11