Harmony: fix spec violation in Math.cosh.

R=jarin@chromium.org
BUG=v8:3141
LOG=N

Review URL: https://codereview.chromium.org/159353003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19272 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/harmony-math.js

@@ -59,8 +59,7 @@ function MathSinh(x) {
 // ES6 draft 09-27-13, section 20.2.2.12.
 function MathCosh(x) {
   if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
-  // Idempotent for NaN and +/-Infinity.
-  if (!NUMBER_IS_FINITE(x)) return x;
+  if (!NUMBER_IS_FINITE(x)) return MathAbs(x);
   return (MathExp(x) + MathExp(-x)) / 2;
 }
 

test/mjsunit/harmony/math-hyperbolic.js

@@ -60,7 +60,7 @@ function test_id(fun, rev, value) {
 });
 
 
-[Math.sinh, Math.asinh, Math.cosh].forEach(function(fun) {
+[Math.sinh, Math.asinh].forEach(function(fun) {
   assertEquals("-Infinity", String(fun(-Infinity)));
   assertEquals("Infinity", String(fun(Infinity)));
   assertEquals("-Infinity", String(fun("-Infinity")));
@@ -68,6 +68,12 @@ function test_id(fun, rev, value) {
 });
 
 
+assertEquals("Infinity", String(Math.cosh(-Infinity)));
+assertEquals("Infinity", String(Math.cosh(Infinity)));
+assertEquals("Infinity", String(Math.cosh("-Infinity")));
+assertEquals("Infinity", String(Math.cosh("Infinity")));
+
+
 assertEquals("-Infinity", String(Math.atanh(-1)));
 assertEquals("Infinity", String(Math.atanh(1)));