[benchmark] Premultiply N for case conversion benchmark

Author: PatrickPijnappel

benchmark/single-source/AngryPhonebook.swift

@@ -26,7 +26,7 @@ public let AngryPhonebook = [
   // Small String Workloads
   BenchmarkInfo(
     name: "AngryPhonebook.ASCII.Small",
-    runFunction: { angryPhonebook($0, ascii) },
+    runFunction: { angryPhonebook($0*10, ascii) },
     tags: t,
     setUpFunction: { blackHole(ascii) }),
   BenchmarkInfo(
@@ -48,7 +48,7 @@ public let AngryPhonebook = [
   // Regular String Workloads
   BenchmarkInfo(
     name: "AngryPhonebook.ASCII",
-    runFunction: { angryPhonebook($0, precomposed: longASCII) },
+    runFunction: { angryPhonebook($0*10, precomposed: longASCII) },
     tags: t,
     setUpFunction: { blackHole(longASCII) }),
   BenchmarkInfo(