src: enable libm trig functions in V8

Should provide better performance on some platforms.

Author: jasnell

benchmark/util/trig.js

@@ -0,0 +1,16 @@
+'use strict';
+
+const { createBenchmark } = require('../common.js');
+const bench = createBenchmark(main, {
+  n: 1_000_000,
+});
+
+function main({ n }) {
+  bench.start();
+  let sum = 0;
+  for (let i = 0; i < n; i++) {
+    const result = Math.sin(Math.PI * i) * Math.cos(Math.PI * i);
+    sum += result;  // eslint-disable-line no-unused-vars
+  }
+  bench.end(n);
+}

common.gypi

@@ -77,6 +77,8 @@
 
     'v8_win64_unwinding_info': 1,
 
+    'v8_use_libm_trig_functions': 1,
+
     # Variables controlling external defines exposed in public headers.
     'v8_enable_map_packing%': 0,
     'v8_enable_pointer_compression_shared_cage%': 0,

test/parallel/test-trig.js

@@ -0,0 +1,14 @@
+'use strict';
+
+require('../common');
+const { strictEqual } = require('assert');
+
+// Test to verify that the trig functions work as expected with the
+// v8_use_libm_trig_functions flag enabled.
+let sum = 0;
+for (let i = 0; i < 1_000_000; i++) {
+  const result = Math.sin(Math.PI * i) * Math.cos(Math.PI * i);
+  sum += result;
+};
+
+strictEqual(sum, -0.00006123284579142155);