Update to v4.19 kernel headers.

Test: Builds and boots.
Change-Id: I99a9ed79666e143b47f02ca4e59eed94f69b7e4a
(cherry picked from commit a981e2e52e2e95a65fa9c9b6fb16dcb4c83dd576)
diff --git a/libc/kernel/uapi/linux/snmp.h b/libc/kernel/uapi/linux/snmp.h
index b9f0c3e..ae24f0f 100644
--- a/libc/kernel/uapi/linux/snmp.h
+++ b/libc/kernel/uapi/linux/snmp.h
@@ -55,6 +55,7 @@
   IPSTATS_MIB_ECT1PKTS,
   IPSTATS_MIB_ECT0PKTS,
   IPSTATS_MIB_CEPKTS,
+  IPSTATS_MIB_REASM_OVERLAPS,
   __IPSTATS_MIB_MAX
 };
 enum {
@@ -243,6 +244,11 @@
   LINUX_MIB_TCPKEEPALIVE,
   LINUX_MIB_TCPMTUPFAIL,
   LINUX_MIB_TCPMTUPSUCCESS,
+  LINUX_MIB_TCPDELIVERED,
+  LINUX_MIB_TCPDELIVEREDCE,
+  LINUX_MIB_TCPACKCOMPRESSED,
+  LINUX_MIB_TCPZEROWINDOWDROP,
+  LINUX_MIB_TCPRCVQDROP,
   __LINUX_MIB_MAX
 };
 enum {