lib: add Math.sumPrecise type definition (ES2025)

Math.sumPrecise is part of the TC39 proposal-math-sum that shipped in ES2025.
Firefox 137+ and Bun have already implemented it, but TypeScript lacks
the corresponding type definition in lib.d.ts.

Adds src/lib/es2025.math.d.ts with the Math interface extension,
and wires it into es2025.d.ts and libs.json.

Fixes #63427

Author: 827652549

src/lib/es2025.d.ts

@@ -2,6 +2,7 @@
 /// <reference lib="es2025.collection" />
 /// <reference lib="es2025.float16" />
 /// <reference lib="es2025.intl" />
-/// <reference lib="es2025.iterator" />
+/// <reference lib="es2025.iterator" />
+/// <reference lib="es2025.math" />
 /// <reference lib="es2025.promise" />
 /// <reference lib="es2025.regexp" />

src/lib/es2025.math.d.ts

@@ -0,0 +1,12 @@
+/// <reference lib="es2015.iterable" />
+
+interface Math {
+    /**
+     * Returns the sum of the values in the iterable, using a more precise
+     * summation algorithm than naive floating-point addition.
+     * @param values An iterable of numbers to sum.
+     * @throws {TypeError} If any value in the iterable is not of type Number (e.g. BigInt).
+     * @see https://tc39.es/proposal-math-sum/
+     */
+    sumPrecise(values: Iterable<number>): number;
+}

src/lib/libs.json

@@ -83,7 +83,8 @@
         "es2025.collection",
         "es2025.float16",
         "es2025.intl",
-        "es2025.iterator",
+        "es2025.iterator",
+        "es2025.math",
         "es2025.promise",
         "es2025.regexp",
         "esnext.array",