Add support for OpenHarmony platform

Author: hqzing

nvm.sh

@@ -2253,6 +2253,14 @@ nvm_get_os() {
     AIX\ *) NVM_OS=aix ;;
     CYGWIN* | MSYS* | MINGW*) NVM_OS=win ;;
   esac
+  # OpenHarmony cannot be reliably detected via `uname` because the device
+  # may run either a Linux kernel or a HarmonyOS kernel; detect it from the
+  # userland musl libc instead.
+  local MUSL_LIBC
+  MUSL_LIBC="/lib/ld-musl-aarch64.so.1"
+  if [ -f "${MUSL_LIBC}" ] && command strings "${MUSL_LIBC}" 2>/dev/null | command grep -q "OHOS"; then
+    NVM_OS=openharmony
+  fi
   nvm_echo "${NVM_OS-}"
 }