added double precision tests

tests/transcendentals-6-3.ispc

@@ -0,0 +1,29 @@
+static double double4(uniform double a, uniform double b, uniform double c, 
+                    uniform double d) {
+    double ret = 0;
+    for (uniform int i = 0; i < programCount; i += 4) {
+        ret = insert(ret, i + 0, a);
+        ret = insert(ret, i + 1, b);
+        ret = insert(ret, i + 2, c);
+        ret = insert(ret, i + 3, d);
+    }
+    return ret;
+}
+
+export uniform int width() { return programCount; }
+
+
+bool ok(double x, double ref) { 
+    bool r = (abs(x - ref) < 1d-15) || abs((x-ref)/ref) < 1d-15;
+    if (any(r == false))
+        print("mismatch got %, expected %\n", x, ref);
+    return r;
+}
+
+
+export void f_v(uniform float RET[]) {
+    double v = double4((14.300000190734863d0),(-6.699999809265137d0),(-21.200000762939453d0),(9.000000000000000d0));
+    double ref = double4((-0.1621146247115303d0),(0.9143832254542971d0),(-0.7030295000381365d0),(-0.9111302618846769d0));
+    RET[programIndex] = ok(cos(v), ref) ? 1. : 0.;
+}
+export void result(uniform float RET[]) { RET[programIndex] = 1.; }