[stdlib] Partially ungyb Integers

The new file straucture is similar to that of floating point types,
where protocols live in one file, and concrete types – in another.

Author: moiseev

stdlib/public/core/CMakeLists.txt

@@ -76,7 +76,8 @@ set(SWIFTLIB_ESSENTIAL
   Indices.swift
   InputStream.swift
   IntegerParsing.swift
-  Integers.swift.gyb
+  Integers.swift
+  IntegerTypes.swift.gyb
   Join.swift
   KeyPath.swift
   LazyCollection.swift

stdlib/public/core/GroupInfo.json

@@ -141,6 +141,7 @@
     {
     "Integers": [
       "Integers.swift",
+      "IntegerTypes.swift",
       "IntegerParsing.swift"],
     "Floating": [
       "FloatingPoint.swift",