changing uniform_min and uniform_max implementations for avx targets

tests/min-float-2.ispc

@@ -0,0 +1,18 @@
+
+export uniform int width() { return programCount; }
+
+
+
+export void f_fu(uniform float RET[], uniform float aFOO[], uniform float b) {
+    float a = aFOO[programIndex];
+    RET[programIndex] = min(-10 * (a-3), .1f);
+    RET[width() - 1] = min(-10 * b, 2);
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = -10 * (programIndex - 2);
+    RET[0] = .1;
+    RET[1] = .1;
+    RET[programCount - 1] = -50;
+}
+