cad/PrusaSlicer: unbreak build after 620968a43a5f

Restore the patch accidentally removed due to an out of date comment.
8a4af427075f removed pthread_setname_np references.

src/libslic3r/Thread.cpp:13:10: fatal error: 'tbb/tbb_thread.h' file not found
 #include <tbb/tbb_thread.h>
          ^~~~~~~~~~~~~~~~~~

1 files changed, 41 insertions, 0 deletions

diff --git a/cad/PrusaSlicer/files/patch-src_libslic3r_Thread.cpp b/cad/PrusaSlicer/files/patch-src_libslic3r_Thread.cpp
new file mode 100644
index 000000000000..32ff24bbfd77
--- /dev/null
+++ b/cad/PrusaSlicer/files/patch-src_libslic3r_Thread.cpp
@@ -0,0 +1,41 @@
+--- src/libslic3r/Thread.cpp.orig	2021-07-16 10:14:03 UTC
++++ src/libslic3r/Thread.cpp
+@@ -9,10 +9,10 @@
+ #include <atomic>
+ #include <condition_variable>
+ #include <mutex>
++#include <thread>
++#include <tbb/global_control.h>
+ #include <tbb/parallel_for.h>
+-#include <tbb/tbb_thread.h>
+ #include <tbb/task_arena.h>
+-#include <tbb/task_scheduler_init.h>
+ 
+ #include "Thread.hpp"
+ 
+@@ -206,13 +206,13 @@ void name_tbb_thread_pool_threads()
+ 	nthreads = 1;
+ #endif
+ 
+-	if (nthreads != nthreads_hw) 
+-		new tbb::task_scheduler_init(int(nthreads));
++	if (nthreads != nthreads_hw)
++		tbb::global_control(tbb::global_control::max_allowed_parallelism, nthreads);
+ 
+ 	std::atomic<size_t>		nthreads_running(0);
+ 	std::condition_variable cv;
+ 	std::mutex				cv_m;
+-	auto					master_thread_id = tbb::this_tbb_thread::get_id();
++	auto					master_thread_id = std::this_thread::get_id();
+     tbb::parallel_for(
+         tbb::blocked_range<size_t>(0, nthreads, 1),
+         [&nthreads_running, nthreads, &master_thread_id, &cv, &cv_m](const tbb::blocked_range<size_t> &range) {
+@@ -226,7 +226,7 @@ void name_tbb_thread_pool_threads()
+ 				std::unique_lock<std::mutex> lk(cv_m);
+ 			    cv.wait(lk, [&nthreads_running, nthreads]{return nthreads_running == nthreads;});
+         	}
+-        	auto thread_id = tbb::this_tbb_thread::get_id();
++        	auto thread_id = std::this_thread::get_id();
+ 			if (thread_id == master_thread_id) {
+ 				// The calling thread runs the 0'th task.
+ 				assert(range.begin() == 0);