Linux fixes. Thanks to Rico Tzschichholz.

src/nvcore/DefsGnucLinux.h

@@ -2,6 +2,7 @@
 #error "Do not include this file directly."
 #endif
 
+#include <stdint.h> // uint8_t, int8_t, ... uintptr_t
 #include <cstddef> // operator new, size_t, NULL
 
 // Function linkage

src/nvthread/nvthread.cpp

@@ -9,6 +9,9 @@
 #elif NV_OS_UNIX
 #include <sys/types.h>
 #include <sys/sysctl.h>
+#if NV_OS_LINUX
+#include <unistd.h>
+#endif
 #endif