[COMMIT osv master] libc: export errno symbol

[Commit Bot]

From: Waldemar Kozaczuk <jwkoz...@gmail.com>
Committer: Waldemar Kozaczuk <jwkoz...@gmail.com>
Branch: master

libc: export errno symbol

When working on hiding most symbols from kernel and building with
conf_hide_symbols=1, I annotated the errno symbol with HIDDEN macro.
This was a mistake as errno should be exported just like libc does it.

So this patch exports the errno back and adds it to the list of
the exported symbols.

Signed-off-by: Waldemar Kozaczuk <jwkoz...@gmail.com>

---
diff --git a/exported_symbols/osv_ld-musl.so.1.symbols b/exported_symbols/osv_ld-musl.so.1.symbols
--- a/exported_symbols/osv_ld-musl.so.1.symbols
+++ b/exported_symbols/osv_ld-musl.so.1.symbols
@@ -154,6 +154,7 @@ erfcl
erff
erfl
__errno_location
+errno
euidaccess
eventfd
eventfd_read
diff --git a/exported_symbols/osv_libc.so.6.symbols b/exported_symbols/osv_libc.so.6.symbols
--- a/exported_symbols/osv_libc.so.6.symbols
+++ b/exported_symbols/osv_libc.so.6.symbols
@@ -111,6 +111,7 @@ epoll_pwait
epoll_wait
erand48
__errno_location
+errno
error
euidaccess
eventfd
diff --git a/libc/libc.cc b/libc/libc.cc
--- a/libc/libc.cc
+++ b/libc/libc.cc
@@ -43,7 +43,6 @@ int libc_error(int err)

#undef errno

-OSV_HIDDEN
int __thread errno;

int* __errno_location()