Move custom features to its own file we can import from other projects.

boost-context-features.jam

@@ -0,0 +1,60 @@
+# Copyright René Ferdinand Rivera Morell 2023-2024
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or copy at
+# http://www.boost.org/LICENSE_1_0.txt)
+
+import feature ;
+import os ;
+
+feature.feature segmented-stacks : on : optional propagated composite ;
+feature.compose <segmented-stacks>on : <define>BOOST_USE_SEGMENTED_STACKS ;
+
+feature.feature htm : tsx : optional propagated composite ;
+feature.compose <htm>tsx : <define>BOOST_USE_TSX ;
+
+feature.feature valgrind : on : optional propagated composite ;
+feature.compose <valgrind>on : <define>BOOST_USE_VALGRIND ;
+
+local rule default_binary_format ( )
+{
+    local tmp = elf ;
+    if [ os.name ] = "NT" { tmp = pe ; }
+    else if [ os.name ] = "CYGWIN" { tmp = pe ; }
+    else if [ os.name ] = "AIX" { tmp = xcoff ; }
+    else if [ os.name ] = "MACOSX" { tmp = mach-o ; }
+    return $(tmp) ;
+}
+
+feature.feature binary-format
+   : elf
+     mach-o
+     pe
+     xcoff
+   : propagated
+   ;
+feature.set-default binary-format : [ default_binary_format ] ;
+
+local rule default_abi ( )
+{
+    local tmp = sysv ;
+    if [ os.name ] = "NT" { tmp = ms ; }
+    else if [ os.name ] = "CYGWIN" { tmp = ms ; }
+    else if [ os.platform ] in "ARM" "ARM64" { tmp = aapcs ; }
+    else if [ os.platform ] = "MIPS32" { tmp = o32 ; }
+    else if [ os.platform ] = "MIPS64" { tmp = n64 ; }
+    return $(tmp) ;
+}
+
+feature.feature abi
+   : aapcs
+     eabi
+     ms
+     n32
+     n64
+     o32
+     o64
+     sysv
+     x32
+   : propagated
+   ;
+feature.set-default abi : [ default_abi ] ;