Fix Number.is* to accept unknown again (microsoft#34932)

Fixes microsoft#34931

This essentially reapplies microsoft#24436 which incorrectly updated the generated files rather than the sources, and so was wiped out by 2f73986.

Note that this is specifically _not_ the same as microsoft#4002, which pertains to the global functions that coerce their arguments and therefore should _not_ accept `unknown`.  This change was already accepted 18 months ago, but was applied incorrectly.

Author: shicks

src/lib/es2015.core.d.ts

@@ -213,27 +213,27 @@ interface NumberConstructor {
      * number. Only finite values of the type number, result in true.
      * @param number A numeric value.
      */
-    isFinite(number: number): boolean;
+    isFinite(number: unknown): boolean;
 
     /**
      * Returns true if the value passed is an integer, false otherwise.
      * @param number A numeric value.
      */
-    isInteger(number: number): boolean;
+    isInteger(number: unknown): boolean;
 
     /**
      * Returns a Boolean value that indicates whether a value is the reserved value NaN (not a
      * number). Unlike the global isNaN(), Number.isNaN() doesn't forcefully convert the parameter
      * to a number. Only values of the type number, that are also NaN, result in true.
      * @param number A numeric value.
      */
-    isNaN(number: number): boolean;
+    isNaN(number: unknown): boolean;
 
     /**
      * Returns true if the value passed is a safe integer.
      * @param number A numeric value.
      */
-    isSafeInteger(number: number): boolean;
+    isSafeInteger(number: unknown): boolean;
 
     /**
      * The value of the largest integer n such that n and n + 1 are both exactly representable as