added double precision tests

tests/transcendentals-5-2.ispc

@@ -0,0 +1,28 @@
+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) < 1e-14) || abs((x-ref)/ref) < 1e-14;
+    if (any(r == false))
+        print("mismatch got %, expected %\n", x, ref);
+    return r;
+}
+
+export void f_v(uniform float RET[]) {
+    double v = double4((-9.424777984619141d0),(4.000000000000000d0),(10.000000000000000d0),(-10.000000000000000d0));
+    double ref = double4((2.3849760909612067d-08),(-0.7568024953079282d0),(-0.5440211108893699d0),(0.5440211108893699d0));
+    RET[programIndex] = ok(sin(v), ref) ? 1. : 0.;
+}
+export void result(uniform float RET[]) { RET[programIndex] = 1.; }