[libcxx] Fix intrinsics for MSVC

[halyavin]

Summary

The parameter was previously renamed but MSVC path was not updated.

[smeenai]

Are you actually using libc++ with cl? :)

[halyavin]

In D40774#943993, @smeenai wrote:

Are you actually using libc++ with cl? :)

People mostly use it to compile on Windows but I heard someone launches the result too. Since no one complains and it passed most of the testing, I guess the result doesn't explode. It is also part of catboost but I haven't tried how well it works there myself yet.

[smeenai]

In D40774#944749, @halyavin wrote:

In D40774#943993, @smeenai wrote:

Are you actually using libc++ with cl? :)

People mostly use it to compile on Windows but I heard someone launches the result too. Since no one complains and it passed most of the testing, I guess the result doesn't explode. It is also part of catboost but I haven't tried how well it works there myself yet.

Hmm how is #include_next handled?

[halyavin]

In D40774#944751, @smeenai wrote:

In D40774#944749, @halyavin wrote:

In D40774#943993, @smeenai wrote:

Are you actually using libc++ with cl? :)

People mostly use it to compile on Windows but I heard someone launches the result too. Since no one complains and it passed most of the testing, I guess the result doesn't explode. It is also part of catboost but I haven't tried how well it works there myself yet.

Hmm how is #include_next handled?

About the same way as this proposed change: https://reviews.llvm.org/D32411 .

PS Could you please commit this (D40774) change? I don't have commit rights.

[smeenai]

In D40774#945254, @halyavin wrote:

In D40774#944751, @smeenai wrote:

In D40774#944749, @halyavin wrote:

In D40774#943993, @smeenai wrote:

Are you actually using libc++ with cl? :)

People mostly use it to compile on Windows but I heard someone launches the result too. Since no one complains and it passed most of the testing, I guess the result doesn't explode. It is also part of catboost but I haven't tried how well it works there myself yet.

Hmm how is #include_next handled?

About the same way as this proposed change: https://reviews.llvm.org/D32411 .

PS Could you please commit this (D40774) change? I don't have commit rights.

Ah, that's good to know. CC @bcraig

Sorry, didn't know you didn't have commit access. I'll commit it for you.

include/algorithm

 #ifndef _LIBCPP_COMPILER_MSVC
     return static_cast<unsigned>(__builtin_ctz(__x));
 #else
   static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
   static_assert(sizeof(unsigned long) == 4, "");
   unsigned long where;
   // Search from LSB to MSB for first set bit.
   // Returns zero if no set bit is found.
-  if (_BitScanForward(&where, mask))
+  if (_BitScanForward(&where, __x))
     return where;
   return 32;
 #endif
 }
 
 inline _LIBCPP_INLINE_VISIBILITY
 unsigned long __ctz(unsigned long __x) {
 #ifndef _LIBCPP_COMPILER_MSVC

 #ifndef _LIBCPP_COMPILER_MSVC
     return static_cast<unsigned long long>(__builtin_ctzll(__x));
 #else
     unsigned long where;
 // Search from LSB to MSB for first set bit.
 // Returns zero if no set bit is found.
 #if defined(_LIBCPP_HAS_BITSCAN64)
     (defined(_M_AMD64) || defined(__x86_64__))
-  if (_BitScanForward64(&where, mask))
+  if (_BitScanForward64(&where, __x))
     return static_cast<int>(where);
 #else
   // Win32 doesn't have _BitScanForward64 so emulate it with two 32 bit calls.
   // Scan the Low Word.
-  if (_BitScanForward(&where, static_cast<unsigned long>(mask)))
+  if (_BitScanForward(&where, static_cast<unsigned long>(__x)))
     return where;
   // Scan the High Word.
-  if (_BitScanForward(&where, static_cast<unsigned long>(mask >> 32)))
+  if (_BitScanForward(&where, static_cast<unsigned long>(__x >> 32)))
     return where + 32; // Create a bit offset from the LSB.
 #endif
   return 64;
 #endif // _LIBCPP_COMPILER_MSVC
 }
 
 // Precondition:  __x != 0
 inline _LIBCPP_INLINE_VISIBILITY
 unsigned __clz(unsigned __x) {
 #ifndef _LIBCPP_COMPILER_MSVC
     return static_cast<unsigned>(__builtin_clz(__x));
 #else
   static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
   static_assert(sizeof(unsigned long) == 4, "");
   unsigned long where;
   // Search from LSB to MSB for first set bit.
   // Returns zero if no set bit is found.
-  if (_BitScanReverse(&where, mask))
+  if (_BitScanReverse(&where, __x))
     return 31 - where;
   return 32; // Undefined Behavior.
 #endif
 }
 
 inline _LIBCPP_INLINE_VISIBILITY
 unsigned long __clz(unsigned long __x) {
 #ifndef _LIBCPP_COMPILER_MSVC
     return static_cast<unsigned long>(__builtin_clzl (__x));
 #else
     static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
     return __clz(static_cast<unsigned>(__x));
 #endif
 }
 
 inline _LIBCPP_INLINE_VISIBILITY
 unsigned long long __clz(unsigned long long __x) {
 #ifndef _LIBCPP_COMPILER_MSVC
     return static_cast<unsigned long long>(__builtin_clzll(__x));
 #else
   unsigned long where;
 // BitScanReverse scans from MSB to LSB for first set bit.
 // Returns 0 if no set bit is found.
 #if defined(_LIBCPP_HAS_BITSCAN64)
-  if (_BitScanReverse64(&where, mask))
+  if (_BitScanReverse64(&where, __x))
     return static_cast<int>(63 - where);
 #else
   // Scan the high 32 bits.
-  if (_BitScanReverse(&where, static_cast<unsigned long>(mask >> 32)))
+  if (_BitScanReverse(&where, static_cast<unsigned long>(__x >> 32)))
     return 63 - (where + 32); // Create a bit offset from the MSB.
   // Scan the low 32 bits.
-  if (_BitScanReverse(&where, static_cast<unsigned long>(mask)))
+  if (_BitScanReverse(&where, static_cast<unsigned long>(__x)))
     return 63 - where;
 #endif
   return 64; // Undefined Behavior.
 #endif // _LIBCPP_COMPILER_MSVC
 }
 
 inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned __x) {
 #ifndef _LIBCPP_COMPILER_MSVC