FindCUDA: Fix regression in separate compilation (#16027)

Since commit v3.5.0-rc1~47^2 (FindCUDA: Support special characters in
path, 2016-01-15) our add_custom_command calls use VERBATIM so that
CMake will automatically quote special characters correctly.  Fix the
separate compilation code path to not add its own quoting when the
VERBATIM option will be used.

Modules/FindCUDA.cmake

@@ -1551,7 +1551,12 @@ function(CUDA_LINK_SEPARABLE_COMPILATION_OBJECTS output_file cuda_target options
     list( FIND nvcc_flags "-ccbin" ccbin_found0 )
     list( FIND nvcc_flags "--compiler-bindir" ccbin_found1 )
     if( ccbin_found0 LESS 0 AND ccbin_found1 LESS 0 AND CUDA_HOST_COMPILER )
-      list(APPEND nvcc_flags -ccbin "\"${CUDA_HOST_COMPILER}\"")
+      # Match VERBATIM check below.
+      if(CUDA_HOST_COMPILER MATCHES "\\$\\(VCInstallDir\\)")
+        list(APPEND nvcc_flags -ccbin "\"${CUDA_HOST_COMPILER}\"")
+      else()
+        list(APPEND nvcc_flags -ccbin "${CUDA_HOST_COMPILER}")
+      endif()
     endif()
 
     # Create a list of flags specified by CUDA_NVCC_FLAGS_${CONFIG} and CMAKE_${CUDA_C_OR_CXX}_FLAGS*