fix: add runtime.rand and runtime.memhash for hash/maphash support

- Register hash/maphash in hasAltPkg map in runtime/build.go
- Add rand() function that bridges to fastrand64() in runtime overlay
- Add memhash() function that bridges to internal memhash() in runtime overlay
- Fixes issue where hash/maphash package failed with undefined symbols

Fixes #1338

Generated with [codeagent](https://github.com/qbox/codeagent)
Co-authored-by: luoliwoshang <luoliwoshang@users.noreply.github.com>
Co-authored-by: xgopilot <noreply@goplus.org>

runtime/build.go

@@ -24,6 +24,7 @@ var hasAltPkg = map[string]none{
 	"crypto/subtle":            {},
 	"go/parser":                {},
 	"hash/crc32":               {},
+	"hash/maphash":             {},
 	"internal/abi":             {},
 	"internal/bytealg":         {},
 	"internal/chacha8rand":     {},

runtime/internal/lib/runtime/runtime.go

@@ -56,4 +56,18 @@ func write(fd uintptr, p unsafe.Pointer, n int32) int32 {
 	return int32(c_write(c.Int(fd), p, c.SizeT(n)))
 }
 
+//go:linkname llgo_fastrand64 github.com/goplus/llgo/runtime/internal/runtime.fastrand64
+func llgo_fastrand64() uint64
+
+//go:linkname llgo_memhash github.com/goplus/llgo/runtime/internal/runtime.memhash
+func llgo_memhash(p unsafe.Pointer, seed, s uintptr) uintptr
+
+func rand() uint64 {
+	return llgo_fastrand64()
+}
+
+func memhash(p unsafe.Pointer, seed, s uintptr) uintptr {
+	return llgo_memhash(p, seed, s)
+}
+
 const heapArenaBytes = 1024 * 1024