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/cmath b/include/cmath
index ffb1c46..917928a 100644
--- a/include/cmath
+++ b/include/cmath
@@ -547,7 +547,7 @@
 #endif
 
 template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
+_LIBCPP_ALWAYS_INLINE
 _LIBCPP_CONSTEXPR typename enable_if<is_floating_point<_A1>::value, bool>::type
 __libcpp_isnan_or_builtin(_A1 __lcpp_x) _NOEXCEPT
 {
@@ -559,7 +559,7 @@
 }
 
 template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
+_LIBCPP_ALWAYS_INLINE
 _LIBCPP_CONSTEXPR typename enable_if<!is_floating_point<_A1>::value, bool>::type
 __libcpp_isnan_or_builtin(_A1 __lcpp_x) _NOEXCEPT
 {
@@ -567,7 +567,7 @@
 }
 
 template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
+_LIBCPP_ALWAYS_INLINE
 _LIBCPP_CONSTEXPR typename enable_if<is_floating_point<_A1>::value, bool>::type
 __libcpp_isinf_or_builtin(_A1 __lcpp_x) _NOEXCEPT
 {
@@ -579,7 +579,7 @@
 }
 
 template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
+_LIBCPP_ALWAYS_INLINE
 _LIBCPP_CONSTEXPR typename enable_if<!is_floating_point<_A1>::value, bool>::type
 __libcpp_isinf_or_builtin(_A1 __lcpp_x) _NOEXCEPT
 {
@@ -587,7 +587,7 @@
 }
 
 template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
+_LIBCPP_ALWAYS_INLINE
 _LIBCPP_CONSTEXPR typename enable_if<is_floating_point<_A1>::value, bool>::type
 __libcpp_isfinite_or_builtin(_A1 __lcpp_x) _NOEXCEPT
 {
@@ -599,7 +599,7 @@
 }
 
 template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
+_LIBCPP_ALWAYS_INLINE
 _LIBCPP_CONSTEXPR typename enable_if<!is_floating_point<_A1>::value, bool>::type
 __libcpp_isfinite_or_builtin(_A1 __lcpp_x) _NOEXCEPT
 {