package/webkitgtk: needs NPTL

Fixes build error

/home/buildroot/buildroot/output/build/webkitgtk-2.44.2/Source/WTF/wtf/StackBounds.cpp: In static member function 'static WTF::StackBounds WTF::StackBounds::newThreadStackBounds(WTF::PlatformThreadHandle)':
/home/buildroot/buildroot/output/build/webkitgtk-2.44.2/Source/WTF/wtf/StackBounds.cpp:117:5: error: 'pthread_getattr_np' was not declared in this scope; did you mean 'pthread_attr_t'?
  117 |     pthread_getattr_np(thread, &sattr);

using this defconfig (and libvpx bump to 1.15.0 reverted)

BR2_arm=y
BR2_TOOLCHAIN_BUILDROOT_UCLIBC=y
BR2_TOOLCHAIN_BUILDROOT_WCHAR=y
BR2_PTHREADS=y
BR2_TOOLCHAIN_BUILDROOT_CXX=y
BR2_PER_PACKAGE_DIRECTORIES=y
BR2_PACKAGE_XORG7=y
BR2_PACKAGE_RPI_USERLAND=y
BR2_PACKAGE_LIBGTK3=y
BR2_PACKAGE_WEBKITGTK=y

A backport of this patch should be considered because the code is
present since 2011:
https://github.com/WebKit/WebKit/blame/03f678fac7076e4d69318bfaae065e4c0eab0f9e/Source/WTF/wtf/StackBounds.cpp#L117

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Julien Olivain <ju.o@free.fr>
(cherry picked from commit 054e5c4d22e9e235d1818baa1333ca4abace50ea)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/webkitgtk/Config.in

@@ -16,11 +16,11 @@ config BR2_PACKAGE_WEBKITGTK_ARCH_SUPPORTS
 	depends on BR2_TOOLCHAIN_HAS_SYNC_4
 	depends on BR2_PACKAGE_LIBGPG_ERROR_ARCH_SUPPORTS # libgcrypt
 
-comment "webkitgtk needs libgtk3 and a toolchain w/ C++, wchar, threads, dynamic library, gcc >= 10, host gcc >= 4.9"
+comment "webkitgtk needs libgtk3 and a toolchain w/ C++, wchar, NPTL, dynamic library, gcc >= 10, host gcc >= 4.9"
 	depends on BR2_PACKAGE_WEBKITGTK_ARCH_SUPPORTS
 	depends on !BR2_BINFMT_FLAT
 	depends on !BR2_PACKAGE_LIBGTK3 || !BR2_INSTALL_LIBSTDCPP || \
-		!BR2_USE_WCHAR || !BR2_TOOLCHAIN_HAS_THREADS || BR2_STATIC_LIBS || \
+		!BR2_USE_WCHAR || !BR2_TOOLCHAIN_HAS_THREADS_NPTL || BR2_STATIC_LIBS || \
 		!BR2_TOOLCHAIN_GCC_AT_LEAST_10 || \
 		!BR2_HOST_GCC_AT_LEAST_4_9
 	depends on BR2_USE_MMU
@@ -32,7 +32,7 @@ config BR2_PACKAGE_WEBKITGTK
 	depends on BR2_PACKAGE_HAS_LIBEGL
 	depends on BR2_HOST_GCC_AT_LEAST_4_9 # icu, host-ruby
 	depends on BR2_INSTALL_LIBSTDCPP
-	depends on BR2_TOOLCHAIN_HAS_THREADS # wayland, icu, libsoup3
+	depends on BR2_TOOLCHAIN_HAS_THREADS_NPTL
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_10
 	depends on BR2_USE_WCHAR # icu, libsoup3
 	depends on BR2_PACKAGE_LIBGTK3