Remove the unused callstack

[milseman]

The call stack was vestigial.

[milseman]

Odd smattering of benchmark results, but overall an improvement. It's also possible there's just enough variability on my machine. Perf relative to #789

=== Regressions ======================================================================
- IntersectionCCC_All                     5.36ms	5.09ms	271µs		5.3%
- IntersectionCCC_All_Scalar              5.36ms	5.1ms	265µs		5.2%
- SubtractionCCC_All                      5.68ms	5.47ms	210µs		3.8%
- SubtractionCCC_All_Scalar               5.68ms	5.48ms	196µs		3.6%
- AnchoredNotFound_All                    8.12ms	7.96ms	159µs		2.0%
- NotFound_All                            3.62ms	3.5ms	112µs		3.2%
- NotFound_All_Scalar                     2.53ms	2.45ms	82.7µs		3.4%
- Css_All                                 2.4ms	2.32ms	81.7µs		3.5%
- Css_All_Scalar                          2.15ms	2.07ms	80.8µs		3.9%
- IPv6Address_Scalar                      1.89ms	1.81ms	71.5µs		3.9%
- GraphemeBreakNoCap_All                  1.67ms	1.6ms	71.3µs		4.5%
- IPv6Address                             1.99ms	1.92ms	66.7µs		3.5%
- MACAddress                              1.94ms	1.88ms	63.8µs		3.4%
- HangulSyllable_All                      2.71ms	2.65ms	62.6µs		2.4%
- URLWithWordBoundaries_All_Scalar        1.7ms	1.64ms	58.9µs		3.6%
- GraphemeBreakNoCap_All_Scalar           1.59ms	1.53ms	57.5µs		3.8%
- URLWithWordBoundaries_All               1.82ms	1.77ms	56.4µs		3.2%
- Lines_All                               860µs	809µs	50.9µs		6.3%
- MACAddress_Scalar                       1.87ms	1.82ms	46.8µs		2.6%
- LiteralSearchNotFound_All               2.58ms	2.54ms	39.4µs		1.5%
- Numbers_All_Scalar                      2.08ms	2.05ms	31.4µs		1.5%
- IPv4Address_Scalar                      1.52ms	1.49ms	28.5µs		1.9%
- IPv4Address                             1.59ms	1.56ms	27.8µs		1.8%
- HangulSyllable_First                    1.25ms	1.22ms	25.4µs		2.1%
- URLWithWordBoundaries_All_SimpleWordBoundaries 572µs	558µs	13.7µs		2.5%
=== Improvements =====================================================================
- EmailRFCNoMatches_All                   42.9ms	46.6ms	-3.67ms		-7.9%
- EmailRFCNoMatches_All_Scalar            39.6ms	43.1ms	-3.54ms		-8.2%
- EmojiRegex_All_Scalar                   36.8ms	40.3ms	-3.43ms		-8.5%
- EmailRFC_All_Scalar                     28.4ms	31.4ms	-3ms		-9.6%
- EmojiRegex_All                          74.7ms	76ms	-1.33ms		-1.7%
- CompilerMessages_All_Scalar             73.7ms	74.8ms	-1.03ms		-1.4%
- EmailRFC_All                            30.1ms	31ms	-938µs		-3.0%
- symDiffCCC_All                          15.2ms	16ms	-877µs		-5.5%
- EmailLookahead_All_Scalar               16.9ms	17.6ms	-740µs		-4.2%
- symDiffCCC_All_Scalar                   15.3ms	16ms	-713µs		-4.4%
- EmailLookahead_All                      18ms	18.6ms	-625µs		-3.4%
- EmailBuiltinCharacterClass_All_Scalar   8.52ms	9.06ms	-540µs		-6.0%
- ReluctantQuantWithTerminal_Whole        5.19ms	5.68ms	-488µs		-8.6%
- ReluctantQuantWithTerminal_Whole_Scalar 5.19ms	5.68ms	-487µs		-8.6%
- CompilerMessages_All                    83.4ms	83.8ms	-371µs		-0.4%
- EmailLookaheadNoMatches_All_Scalar      18.2ms	18.4ms	-274µs		-1.5%
- Words_All_Scalar                        4.47ms	4.71ms	-241µs		-5.1%
- DiceRollsInText_All_Scalar              26.1ms	26.3ms	-198µs		-0.8%
- EmailLookaheadNoMatches_All             19.9ms	20ms	-153µs		-0.8%
- InvertedCCC_All_Scalar                  5.59ms	5.72ms	-132µs		-2.3%
- InvertedCCC_All                         5.62ms	5.7ms	-77.8µs		-1.4%
- DiceNotation_Scalar                     3.25ms	3.32ms	-70.1µs		-2.1%
- ReluctantQuant_Whole                    3.36ms	3.42ms	-66.5µs		-1.9%
- FSPathsRegex_Scalar                     3.19ms	3.25ms	-62µs		-1.9%
- BasicBuiltinCharacterClass_All_Scalar   2.33ms	2.39ms	-58.8µs		-2.5%
- FSPathsRegexFound_Scalar                2.94ms	3ms	-58.7µs		-2.0%
- EmailBuiltinCharacterClass_All          8.75ms	8.81ms	-58.4µs		-0.7%
- DiceNotation                            3.4ms	3.46ms	-57.6µs		-1.7%
- ReluctantQuant_Whole_Scalar             3.36ms	3.41ms	-50.5µs		-1.5%
- EmailLookaheadList_Scalar               3.34ms	3.37ms	-29.3µs		-0.9%
- EmailLookaheadList                      3.46ms	3.48ms	-21.8µs		-0.6%
- LiteralSearch_All_Scalar                1.64ms	1.66ms	-18.2µs		-1.1%

[milseman]

@swift-ci please test