[libc++] Remove Lit annotations for unsupported GCC versions from the test suite

Since we officially don't support several older compilers now, we can
drop a lot of the markup in the test suite. This helps keep the test
suite simple and makes sure that UNSUPPORTED annotations don't rot.

This is the first patch of a series that will remove annotations for
compilers that are now unsupported.

Differential Revision: https://reviews.llvm.org/D107787

Author: ldionne

libcxx/test/libcxx/diagnostics/enable_nodiscard.verify.cpp

@@ -13,9 +13,6 @@
 
 // UNSUPPORTED: c++03
 
-// GCC 7 is the first version to introduce [[nodiscard]]
-// UNSUPPORTED: gcc-5, gcc-6
-
 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_NODISCARD
 
 #include <__config>

libcxx/test/libcxx/diagnostics/enable_nodiscard_disable_after_cxx17.verify.cpp

@@ -9,9 +9,6 @@
 
 // UNSUPPORTED: c++03
 
-// GCC 7 is the first version to introduce [[nodiscard]]
-// UNSUPPORTED: gcc-5, gcc-6
-
 // Test that _LIBCPP_DISABLE_NODISCARD_EXT only disables _LIBCPP_NODISCARD_EXT
 // and not _LIBCPP_NODISCARD_AFTER_CXX17.
 

libcxx/test/libcxx/diagnostics/enable_nodiscard_disable_nodiscard_ext.verify.cpp

@@ -9,10 +9,6 @@
 
 // UNSUPPORTED: c++03
 
-// GCC 7 is the first version to introduce [[nodiscard]]
-// UNSUPPORTED: gcc-5, gcc-6
-
-
 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_NODISCARD
 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_NODISCARD_EXT
 #include <__config>

libcxx/test/libcxx/diagnostics/nodiscard_extensions.pass.cpp

@@ -16,7 +16,6 @@
 // AppleClang9 and GCC 5 don't support C++17's implicitly synthesized
 // deduction guides from existing ctors, needed by default_searcher() below.
 // UNSUPPORTED: apple-clang-9
-// UNSUPPORTED: gcc-5
 
 // All entities to which libc++ applies [[nodiscard]] as an extension should
 // be tested here and in nodiscard_extensions.fail.cpp. They should also

libcxx/test/libcxx/double_include.sh.cpp

@@ -14,11 +14,6 @@
 // RUN: %{cxx} -o %t.exe %t.first.o %t.second.o %{flags} %{link_flags}
 // RUN: %{run}
 
-// GCC 5 pretends it supports C++17 features, but some features like static_assert
-// without a message are not actually supported. This causes some headers to fail
-// when included.
-// UNSUPPORTED: gcc-5 && c++17
-
 // Prevent <ext/hash_map> from generating deprecated warnings for this test.
 #if defined(__DEPRECATED)
 #    undef __DEPRECATED

libcxx/test/libcxx/input.output/filesystems/convert_file_time.pass.cpp

@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11
-// UNSUPPORTED: gcc-5
 
 // <filesystem>
 

libcxx/test/libcxx/iterators/iterator.concepts/iterator.concept.random.access/subsumption.compile.pass.cpp

@@ -8,7 +8,6 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 // UNSUPPORTED: libcpp-no-concepts
-// UNSUPPORTED: gcc-10
 
 // template<class T>
 // concept random_access_iterator;

libcxx/test/libcxx/iterators/iterator.requirements/iterator.assoc.types/iterator.traits/legacy_bidirectional_iterator.compile.pass.cpp

@@ -8,7 +8,6 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 // UNSUPPORTED: libcpp-no-concepts
-// UNSUPPORTED: gcc-10
 
 // template<class I>
 // concept __iterator_traits_detail::__cpp17_bidirectional_iterator;

libcxx/test/libcxx/iterators/iterator.requirements/iterator.assoc.types/iterator.traits/legacy_forward_iterator.compile.pass.cpp

@@ -8,7 +8,6 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 // UNSUPPORTED: libcpp-no-concepts
-// UNSUPPORTED: gcc-10
 
 // template<class I>
 // concept __iterator_traits_detail::__cpp17_forward_iterator;

libcxx/test/libcxx/iterators/iterator.requirements/iterator.assoc.types/iterator.traits/legacy_input_iterator.compile.pass.cpp

@@ -8,7 +8,6 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 // UNSUPPORTED: libcpp-no-concepts
-// UNSUPPORTED: gcc-10
 
 // template<class I>
 // concept __iterator_traits_detail::__cpp17_input_iterator;