configure: add 'embedded' value for --enable-quic

configure.ac

@@ -560,7 +560,7 @@ AS_IF([test "$enable_daemon" = "yes" -o "$enable_utilities" = "yes"], [
 
 # QUIC support
 AC_ARG_ENABLE([quic],
-   AS_HELP_STRING([--enable-quic=auto|yes|no], [Support DoQ (needs libngtcp2 >= 0.15.0, gnutls >= 3.7.2) [default=auto]]),
+   AS_HELP_STRING([--enable-quic=auto|yes|no|embedded], [Support DoQ (needs libngtcp2 >= 0.15.0, gnutls >= 3.7.2) [default=auto]]),
    [], [enable_quic=auto])
 
 AS_CASE([$enable_quic],
@@ -573,6 +573,10 @@ AS_CASE([$enable_quic],
                  libngtcp2_CFLAGS="-I\$(top_srcdir)/src/contrib/libngtcp2"],
                 [enable_quic=no
                  AC_MSG_WARN([gnutls >= 3.7.2 is required for QUIC])]))],
+   [embedded], [enable_quic=embedded
+                embedded_libngtcp2_CFLAGS="-I\$(top_srcdir)/src/contrib/libngtcp2 -I\$(top_srcdir)/src/contrib/libngtcp2/ngtcp2/lib"
+                embedded_libngtcp2_LIBS=$libelf_LIBS
+                libngtcp2_CFLAGS="-I\$(top_srcdir)/src/contrib/libngtcp2"],
    [no], [],
    [*], [AC_MSG_ERROR([Invalid value of --enable-quic.])]
 )