Use POSIX threads in Linux/Genode hybrids

- Let hybrid Linux/Genode programs use POSIX threads for the
  implementation of the Thread API.
- Prevent linkage of cxx library to hybrid Linux/Genode programs because
  the cxx functionality is covered by glibc.

base/include/base/thread.h

@@ -277,6 +277,10 @@ namespace Genode {
 			 * \param name        thread name for debugging
 			 * \param stack_size  stack size
 			 *
+			 * \throw Stack_too_large
+			 * \throw Stack_alloc_failed
+			 * \throw Context_alloc_failed
+			 *
 			 * The stack for the new thread will be allocated from the RAM
 			 * session of the process environment. A small portion of the
 			 * stack size is internally used by the framework for storing

base/mk/prg.mk

@@ -132,6 +132,18 @@ LD_CMD += $(addprefix $(LD_SCRIPT_PREFIX), $(LD_SCRIPTS))
 STATIC_LIBS := $(foreach l,$(FILTER_DEPS),$(LIB_CACHE_DIR)/$l/$l.lib.a)
 STATIC_LIBS := $(sort $(wildcard $(STATIC_LIBS)))
 
+#
+# For hybrid Linux/Genode programs, prevent the linkage of the normal thread
+# library. Because such programs use the glibc, we map Genode's thread API
+# to 'pthreads' instead to improve inter-operability with native Linux
+# libraries. Furthermore, we do not need Genode's cxx library for such
+# programs because the cxx functionality is already provided by the glibc.
+#
+ifeq ($(USE_HOST_LD_SCRIPT),yes)
+STATIC_LIBS := $(filter-out $(LIB_CACHE_DIR)/thread/thread.lib.a, $(STATIC_LIBS))
+STATIC_LIBS := $(filter-out $(LIB_CACHE_DIR)/cxx/cxx.lib.a,       $(STATIC_LIBS))
+endif
+
 #
 # We need the linker option '--whole-archive' to make sure that all library
 # constructors marked with '__attribute__((constructor))' end up int the