[libc][bazel] Mark socket functions weak

Downstream ther'es a user that needs the syscall wrappers to be weak. I
intend to set up a proper mechanism for just listing which functions
should be weak eventually, but for now this is necessary.

Author: michaelrj-google

utils/bazel/llvm-project-overlay/libc/BUILD.bazel

@@ -4650,6 +4650,7 @@ libc_function(
     name = "socket",
     srcs = ["src/sys/socket/linux/socket.cpp"],
     hdrs = ["src/sys/socket/socket.h"],
+    weak = True,
     deps = [
         ":__support_common",
         ":__support_osutil_syscall",
@@ -4661,6 +4662,7 @@ libc_function(
     name = "socketpair",
     srcs = ["src/sys/socket/linux/socketpair.cpp"],
     hdrs = ["src/sys/socket/socketpair.h"],
+    weak = True,
     deps = [
         ":__support_common",
         ":__support_osutil_syscall",
@@ -4672,6 +4674,7 @@ libc_function(
     name = "send",
     srcs = ["src/sys/socket/linux/send.cpp"],
     hdrs = ["src/sys/socket/send.h"],
+    weak = True,
     deps = [
         ":__support_common",
         ":__support_osutil_syscall",
@@ -4686,6 +4689,7 @@ libc_function(
     name = "sendto",
     srcs = ["src/sys/socket/linux/sendto.cpp"],
     hdrs = ["src/sys/socket/sendto.h"],
+    weak = True,
     deps = [
         ":__support_common",
         ":__support_osutil_syscall",
@@ -4700,6 +4704,7 @@ libc_function(
     name = "sendmsg",
     srcs = ["src/sys/socket/linux/sendmsg.cpp"],
     hdrs = ["src/sys/socket/sendmsg.h"],
+    weak = True,
     deps = [
         ":__support_common",
         ":__support_osutil_syscall",
@@ -4713,6 +4718,7 @@ libc_function(
     name = "recv",
     srcs = ["src/sys/socket/linux/recv.cpp"],
     hdrs = ["src/sys/socket/recv.h"],
+    weak = True,
     deps = [
         ":__support_common",
         ":__support_osutil_syscall",
@@ -4727,6 +4733,7 @@ libc_function(
     name = "recvfrom",
     srcs = ["src/sys/socket/linux/recvfrom.cpp"],
     hdrs = ["src/sys/socket/recvfrom.h"],
+    weak = True,
     deps = [
         ":__support_common",
         ":__support_osutil_syscall",
@@ -4741,6 +4748,7 @@ libc_function(
     name = "recvmsg",
     srcs = ["src/sys/socket/linux/recvmsg.cpp"],
     hdrs = ["src/sys/socket/recvmsg.h"],
+    weak = True,
     deps = [
         ":__support_common",
         ":__support_osutil_syscall",