Build file updates. (google#514)

This CL adds a default to shaderc to build in Debug mode if the
build type is not provided. It also sets SPIRV-Headers to not build the
examples folder.

CMakeLists.txt

@@ -2,6 +2,11 @@ cmake_minimum_required(VERSION 2.8.12)
 project(shaderc)
 enable_testing()
 
+if ("${CMAKE_BUILD_TYPE}" STREQUAL "")
+  message(STATUS "No build type selected, default to Debug")
+  set(CMAKE_BUILD_TYPE "Debug")
+endif()
+
 message(STATUS "Shaderc: build type is \"${CMAKE_BUILD_TYPE}\".")
 
 option(SHADERC_SKIP_INSTALL "Skip installation" ${SHADERC_SKIP_INSTALL})

third_party/CMakeLists.txt

@@ -33,6 +33,7 @@ endif()
 set(OLD_PLATFORM_TOOLSET ${CMAKE_GENERATOR_TOOLSET})
 
 if (IS_DIRECTORY ${SHADERC_SPIRV_HEADERS_DIR})
+  set(SPIRV_HEADERS_SKIP_EXAMPLES ON)
   add_subdirectory(${SHADERC_SPIRV_HEADERS_DIR} spirv-headers)
 endif()