Temporarily un-mark tests as XFAIL on Darwin

Author: ldionne

libcxx/test/libcxx/input.output/iostreams.base/ios.base/ios.base.cons/dtor.uninitialized.pass.cpp

@@ -10,7 +10,8 @@
 
 // The fix for issue 57964 requires an updated dylib due to explicit
 // instantiations. That means Apple backdeployment targets remain broken.
-// XFAIL: using-built-library-before-llvm-19
+// TODO: Remove && !darwin once availability markup for LLVM 19 on macOS has been added
+// XFAIL: using-built-library-before-llvm-19 && !darwin
 
 // <ios>
 

libcxx/test/std/input.output/file.streams/fstreams/filebuf.virtuals/setbuf.pass.cpp

@@ -12,7 +12,8 @@
 
 // This test requires the fix to https://llvm.org/PR60509 in the dylib,
 // which landed in 5afb937d8a30445642ccaf33866ee4cdd0713222.
-// XFAIL: using-built-library-before-llvm-19
+// TODO: Remove && !darwin once availability markup for LLVM 19 on macOS has been added
+// XFAIL: using-built-library-before-llvm-19 && !darwin
 
 #include <fstream>
 #include <cstddef>

libcxx/test/std/input.output/iostream.format/input.streams/istream.unformatted/sync.pass.cpp

@@ -13,7 +13,8 @@
 // The fix for bug 51497 and bug 51499 require and updated dylib due to
 // explicit instantiations. That means Apple backdeployment targets remain
 // broken.
-// XFAIL: using-built-library-before-llvm-19
+// TODO: Remove && !darwin once availability markup for LLVM 19 on macOS has been added
+// XFAIL: using-built-library-before-llvm-19 && !darwin
 
 #include <istream>
 #include <cassert>

libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_double.pass.cpp

@@ -8,7 +8,8 @@
 
 // The fix for LWG2381 (https://github.com/llvm/llvm-project/pull/77948) changed behavior of
 // FP parsing. This requires 3e15c97fa3812993bdc319827a5c6d867b765ae8 in the dylib.
-// XFAIL: using-built-library-before-llvm-19
+// TODO: Remove && !darwin once availability markup for LLVM 19 on macOS has been added
+// XFAIL: using-built-library-before-llvm-19 && !darwin
 
 // <locale>
 

libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_float.pass.cpp

@@ -8,7 +8,8 @@
 
 // The fix for LWG2381 (https://github.com/llvm/llvm-project/pull/77948) changed behavior of
 // FP parsing. This requires 3e15c97fa3812993bdc319827a5c6d867b765ae8 in the dylib.
-// XFAIL: using-built-library-before-llvm-19
+// TODO: Remove && !darwin once availability markup for LLVM 19 on macOS has been added
+// XFAIL: using-built-library-before-llvm-19 && !darwin
 
 // <locale>
 

libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_long_double.pass.cpp

@@ -8,7 +8,8 @@
 
 // The fix for LWG2381 (https://github.com/llvm/llvm-project/pull/77948) changed behavior of
 // FP parsing. This requires 3e15c97fa3812993bdc319827a5c6d867b765ae8 in the dylib.
-// XFAIL: using-built-library-before-llvm-19
+// TODO: Remove && !darwin once availability markup for LLVM 19 on macOS has been added
+// XFAIL: using-built-library-before-llvm-19 && !darwin
 
 // <locale>