Add reduce_equal() function to standard library.

tests/reduce-equal-9.ispc

@@ -0,0 +1,15 @@
+
+export uniform int width() { return programCount; }
+
+export void f_fu(uniform float RET[], uniform float aFOO[], uniform float b) {
+    double a = aFOO[programIndex/2];
+    RET[programIndex] = 1;
+    uniform bool eq = false;
+    if (a < 4)
+        eq = reduce_equal(a); 
+    RET[programIndex] = eq;
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 0;
+}