Separate libstdcxx-specific sysincls into dedicated file

build/conf/sysincl.conf

@@ -2,6 +2,7 @@ SYSINCL=
 SYSINCL+=build/sysincl/macro.yml
 SYSINCL+=build/sysincl/libc-to-compat.yml
 SYSINCL+=build/sysincl/libc-to-nothing.yml
+SYSINCL+=build/sysincl/stl-to-libstdcxx.yml
 SYSINCL+=build/sysincl/stl-to-nothing.yml
 SYSINCL+=build/sysincl/linux.yml
 SYSINCL+=build/sysincl/windows.yml

build/sysincl/stl-to-libstdcxx.yml

@@ -0,0 +1,13 @@
+# These headers are included from e. g. contrib/restricted/boost
+# in order to optimize build times when building against libstdc++.
+#
+# In ya make, such builds are supported when building with -DUSE_STL_SYSTEM
+- includes:
+  - bits/atomicity.h
+  - bits/c++config.h
+  - bits/char_traits.h
+  - bits/move.h
+  - bits/stl_algobase.h
+  - bits/stl_function.h
+  - bits/stl_move.h
+  - bits/stl_pair.h

build/sysincl/unsorted.yml

@@ -431,8 +431,6 @@
   - config_auto.h
   #endif
   #if defined(_TRASH_) && TODO
-  - bits/c++config.h
-  - bits/atomicity.h
   - gcrypt.h
   - gnutls/gnutls.h
   - gdwmfapi.h
@@ -480,12 +478,6 @@
   - ../ucrt/sys/stat.h
   - asm/page.h
   - asm/sgidefs.h
-  - bits/char_traits.h
-  - bits/stl_algobase.h
-  - bits/stl_move.h
-  - bits/stl_pair.h
-  - bits/stl_function.h
-  - bits/move.h
   - ndir.h
   - sunmedia_types.h
   - clidef.h