Build fixes for OSL on Windows

This changelist contains two fixes for OSL builds on the Windows platform, both of which were authored by Kai Rohmer at NVIDIA.

Author: jstone-lucasfilm

src/testrender/CMakeLists.txt

@@ -79,7 +79,7 @@ add_executable (testrender ${testrender_srcs})
 
 target_link_libraries (testrender
     PRIVATE
-        oslexec oslquery
+        oslexec oslquery oslcomp
         pugixml::pugixml
         Threads::Threads)
 

src/testshade/CMakeLists.txt

@@ -2,6 +2,8 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # https://github.com/AcademySoftwareFoundation/OpenShadingLanguage
 
+set (LLVM_COMPILE_FLAGS ${LLVM_COMPILE_FLAGS} "-std=c++17")
+
 # The 'testshade' executable
 set ( testshade_srcs
       testshade.cpp