use * for pointer type instead of &

See #770

To help automatically translate code, see the
zig-fmt-pointer-reform-2 branch.

This will convert all & into *. Due to the syntax
ambiguity (which is why we are making this change),
even address-of & will turn into *, so you'll have
to manually fix thes instances. You will be guaranteed
to get compile errors for them - expected 'type', found 'foo'

std/math/complex/sqrt.zig

@@ -15,7 +15,7 @@ pub fn sqrt(z: var) Complex(@typeOf(z.re)) {
     };
 }
 
-fn sqrt32(z: &const Complex(f32)) Complex(f32) {
+fn sqrt32(z: *const Complex(f32)) Complex(f32) {
     const x = z.re;
     const y = z.im;
 
@@ -57,7 +57,7 @@ fn sqrt32(z: &const Complex(f32)) Complex(f32) {
     }
 }
 
-fn sqrt64(z: &const Complex(f64)) Complex(f64) {
+fn sqrt64(z: *const Complex(f64)) Complex(f64) {
     // may encounter overflow for im,re >= DBL_MAX / (1 + sqrt(2))
     const threshold = 0x1.a827999fcef32p+1022;