Match RelWithDebInfo for MSVC builds (#85)

Update build scripts to set the correct flags for the RelWithDebInfo build.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index ca16372..b7c9155 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -87,8 +87,13 @@
   # /MT* options.  For debug builds use /MTd, and for release builds use /MT.
   if(CMAKE_BUILD_TYPE MATCHES "Debug")
     set(CUSTOM_CXX_FLAGS ${CUSTOM_CXX_FLAGS} /MTd)
+    message(STATUS "Setting /MTd")
+  elseif(CMAKE_BUILD_TYPE MATCHES "RelWithDebInfo")
+    set(CUSTOM_CXX_FLAGS ${CUSTOM_CXX_FLAGS} /MT)
+    message(STATUS "Setting /MT")
   else()
     set(CUSTOM_CXX_FLAGS ${CUSTOM_CXX_FLAGS} /MT)
+    message(STATUS "Setting /MT")
   endif()
 
   set(CUSTOM_CXX_FLAGS
diff --git a/third_party/CMakeLists.txt b/third_party/CMakeLists.txt
index 1b7e2f5..886d357 100644
--- a/third_party/CMakeLists.txt
+++ b/third_party/CMakeLists.txt
@@ -12,12 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-if(WIN32)
-  option(g_force_shared_crt
-    "Use shared (DLL) run-time lib even when Google Test is built as static lib."
-    ON)
-endif()
-
 if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
   # Turn off warnings to make gtest happy
   set(GTEST_BUILD_FIXES
@@ -252,6 +246,7 @@
 # Tell Glslang to statically link the C Runtime library.
 set(LLVM_USE_CRT_DEBUG MTd)
 set(LLVM_USE_CRT_RELEASE MT)
+set(LLVM_USE_CRT_RELWITHDEBINFO MT)
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/glslang)
 set(CMAKE_CXX_FLAGS ${CXX_BACK})