wasi preview 2 support (#4027)

* all: wasip2 support

Co-authored-by: Randy Reddig <randy.reddig@fastly.com>

src/crypto/rand/rand_arc4random.go

@@ -1,4 +1,4 @@
-//go:build darwin || tinygo.wasm
+//go:build darwin || wasip1 || wasip2 || wasm
 
 // This implementation of crypto/rand uses the arc4random_buf function
 // (available on both MacOS and WASI) to generate random numbers.

src/crypto/rand/rand_urandom.go

@@ -1,4 +1,4 @@
-//go:build linux && !baremetal && !wasip1
+//go:build linux && !baremetal && !wasip1 && !wasip2
 
 // This implementation of crypto/rand uses the /dev/urandom pseudo-file to
 // generate random numbers.