QUIC: ngx_quic_bpf module.

The quic kernel bpf helper inspects packet payload for DCID, extracts key
and routes the packet into socket matching the key.

Due to reuseport feature, each worker owns a personal socket, which is
identified by the same key, used to create DCID.

BPF objects are locked in RAM and are subject to RLIMIT_MEMLOCK.
The "ulimit -l" command may be used to setup proper limits, if maps
cannot be created with EPERM or updated with ETOOLONG.

auto/modules

@@ -1345,6 +1345,22 @@ if [ $USE_OPENSSL$USE_OPENSSL_QUIC = YESYES ]; then
     ngx_module_order=
 
     . auto/module
+
+    if [ $NGX_QUIC_BPF$BPF_FOUND$SO_COOKIE_FOUND = YESYESYES ]; then
+        ngx_module_type=CORE
+        ngx_module_name=ngx_quic_bpf_module
+        ngx_module_incs=
+        ngx_module_deps=
+        ngx_module_srcs="src/event/quic/ngx_event_quic_bpf.c \
+                         src/event/quic/ngx_event_quic_bpf_code.c"
+        ngx_module_libs=
+        ngx_module_link=YES
+        ngx_module_order=
+
+        . auto/module
+
+        have=NGX_QUIC_BPF . auto/have
+    fi
 fi