Enabled tvOS platform (#4329)

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 55f84e6..3568949 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -48,6 +48,8 @@
   add_definitions(-DSPIRV_MAC)
 elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "iOS")
   add_definitions(-DSPIRV_IOS)
+elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "tvOS")
+  add_definitions(-DSPIRV_TVOS)
 elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Android")
   add_definitions(-DSPIRV_ANDROID)
   set(SPIRV_TIMER_ENABLED ${SPIRV_ALLOW_TIMERS})

source/print.cpp

diff --git a/source/print.cpp b/source/print.cpp
index 128587a..2418c5b 100644
--- a/source/print.cpp
+++ b/source/print.cpp
@@ -15,7 +15,7 @@
 #include "source/print.h"
 
 #if defined(SPIRV_ANDROID) || defined(SPIRV_LINUX) || defined(SPIRV_MAC) || \
-    defined(SPIRV_IOS) || defined(SPIRV_FREEBSD) ||                         \
+    defined(SPIRV_IOS) || defined(SPIRV_TVOS) || defined(SPIRV_FREEBSD) ||  \
     defined(SPIRV_EMSCRIPTEN) || defined(SPIRV_FUCHSIA)
 namespace spvtools {