libffi and python: need threads support

libffi depends on pthreads.

Python depends on libffi (it can provide a builtin libffi, but also depends on
pthreads). Thus this patch also disable Python support if toolchain is compiled
w/o treads support.

Fixes http://sysmic.org/~jezz/results/204099dd:

../src/closures.c:119:21: fatal error: pthread.h: No such file or directory

[Peter: fix comment dependencies, add python3]
Signed-off-by: Jérôme Pouiller <jezz@sysmic.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libffi/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_LIBFFI
 	bool "libffi"
+	depends on BR2_TOOLCHAIN_HAS_THREADS
 	help
 	  The libffi library provides a portable, high level
 	  programming interface to various calling conventions. This
@@ -7,3 +8,6 @@ config BR2_PACKAGE_LIBFFI
 	  interface description at run-time.
 
 	  http://sourceware.org/libffi/
+
+comment "libffi needs a toolchain w/ threads"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS

package/python/Config.in

@@ -3,15 +3,16 @@ config BR2_PACKAGE_PYTHON
 	depends on BR2_USE_WCHAR
 	# uses fork()
 	depends on BR2_USE_MMU
+	depends on BR2_TOOLCHAIN_HAS_THREADS # libffi
 	select BR2_PACKAGE_LIBFFI
 	help
 	  The python language interpreter.
 
 	  http://www.python.org/
 
-comment "python needs a toolchain w/ wchar"
+comment "python needs a toolchain w/ wchar, threads"
 	depends on BR2_USE_MMU
-	depends on !BR2_USE_WCHAR
+	depends on !BR2_USE_WCHAR || !BR2_TOOLCHAIN_HAS_THREADS
 
 if BR2_PACKAGE_PYTHON
 

package/python3/Config.in

@@ -4,15 +4,16 @@ config BR2_PACKAGE_PYTHON3
 	depends on BR2_USE_WCHAR
 	# uses fork()
 	depends on BR2_USE_MMU
+	depends on BR2_TOOLCHAIN_HAS_THREADS # libffi
 	select BR2_PACKAGE_LIBFFI
 	help
 	  The python language interpreter.
 
 	  http://www.python.org/
 
-comment "python3 needs a toolchain w/ wchar"
+comment "python3 needs a toolchain w/ wchar, threads"
 	depends on BR2_USE_MMU
-	depends on !BR2_USE_WCHAR
+	depends on !BR2_USE_WCHAR || !BR2_TOOLCHAIN_HAS_THREADS
 
 if BR2_PACKAGE_PYTHON3