[llvm] [libc][bazel] mark epoll funcitons as weak (PR #81327)

[via llvm-commits]

https://github.com/michaelrj-google created https://github.com/llvm/llvm-project/pull/81327

Downstream there's a user that intercepts these functions and overlays
them. This causes symbol conflicts if neither function is marked weak.
In future the intent is to move to this to being a downstream configuration
option.


>From 351fb06c22943eca4ef72efec8344024de011d07 Mon Sep 17 00:00:00 2001
From: Michael Jones <michaelrj at google.com>
Date: Fri, 9 Feb 2024 14:42:26 -0800
Subject: [PATCH] [libc][bazel] mark epoll funcitons as weak

Downstream there's a user that intercepts these functions and overlays
them. This causes symbol conflicts if neither function is marked weak.
In future the intent is to move to this to being a downstream configuration
option.
---
 utils/bazel/llvm-project-overlay/libc/BUILD.bazel | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index fd6d1dc047f428..e2e1daf365acdc 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -3216,6 +3216,7 @@ libc_function(
     name = "epoll_wait",
     srcs = ["src/sys/epoll/linux/epoll_wait.cpp"],
     hdrs = ["src/sys/epoll/epoll_wait.h"],
+    weak = True,
     deps = [
         ":__support_osutil_syscall",
         ":errno",
@@ -3226,6 +3227,7 @@ libc_function(
     name = "epoll_pwait",
     srcs = ["src/sys/epoll/linux/epoll_pwait.cpp"],
     hdrs = ["src/sys/epoll/epoll_pwait.h"],
+    weak = True,
     deps = [
         ":__support_osutil_syscall",
         ":errno",
@@ -3238,6 +3240,7 @@ libc_function(
 #     name = "epoll_pwait2",
 #     srcs = ["src/sys/epoll/linux/epoll_pwait2.cpp"],
 #     hdrs = ["src/sys/epoll/epoll_pwait2.h"],
+#     weak = True,
 #     deps = [
 #         ":__support_osutil_syscall",
 #         ":errno",