Linux compilation broken b/c of missing <prctl.h>

[amyspark]

As part of afd3a1c, a conditional include was removed from src/libcore/thread.cpp which is necessary for using prtcl() calls in Linux.

mitsuba/src/libcore/thread.cpp

Lines 29 to 36 in 1de9467

	// Required for native thread functions
	#if defined(__LINUX__)
	# include <sys/prctl.h>
	#elif defined(__OSX__)
	# include <pthread.h>
	#elif defined(__WINDOWS__)
	# include <windows.h>
	#endif

mitsuba/src/libcore/thread.cpp

Lines 29 to 34 in afd3a1c

	// Required for native thread functions
	#if defined(__OSX__)
	# include <pthread.h>
	#elif defined(__WINDOWS__)
	# include <windows.h>
	#endif

It seems that there was a prctl call left behind:

mitsuba/src/libcore/thread.cpp

Line 637 in afd3a1c

prctl(PR_SET_NAME, threadName.c_str());

A pull request is forthcoming.