Revert "[libc++] Replace uses of _LIBCPP_ALWAYS_INLINE by _LIBCPP_INLINE_VISIBILITY"

This reverts commit r336369. The commit had two problems:
1. __pbump was marked as _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY instead of
   _LIBCPP_INLINE_VISIBILITY, which lead to two symbols being added in the
   dylib and the check-cxx-abilist failing.

2. The LLDB tests started failing because they undefine
   `_LIBCPP_INLINE_VISIBILITY`. I need to figure out why they do that and
   fix the tests before we can go forward with this change.

llvm-svn: 336382
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 195a499d638db5157a64c9c816b76154096ecd52
diff --git a/include/regex b/include/regex
index 84aacc0..612fa84 100644
--- a/include/regex
+++ b/include/regex
@@ -968,7 +968,7 @@
 };
 
 template <regex_constants::error_type _Ev>
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NORETURN inline _LIBCPP_ALWAYS_INLINE
 void __throw_regex_error()
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS