LuaDrawstring optimization #3152

Job	Run time
Linux (Debug, gcc-5)	7m 40s
Windows (Debug, MSVC, Win32)	16m 25s
Linux (Debug, gcc-10)	7m 46s
Mac (Debug, clang, x86_64)	7m 34s
Windows (Debug, MSVC, x64)	16m 9s
Linux (Debug, clang-9)	7m 22s
Mac (Release, clang, x86_64)	7m 29s
Windows (Release, MSVC, Win32)	31m 30s
Linux (Release, gcc-5)	7m 18s
Windows (Release, MSVC, x64)	26m 29s
Linux (Release, gcc-10)	7m 28s
Linux (Release, clang-9)	7m 25s
Linux (Debug, gcc-10, -DFSO_BUILD_WITH_OPENGL=OFF -DFSO_BUILD_WITH_VULKAN=OFF)	7m 42s
Linux (Release, gcc-10, -DFSO_BUILD_WITH_OPENGL=OFF -DFSO_BUILD_WITH_VULKAN=OFF)	7m 25s
	2h 45m 42s

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