cmake: initial version of luzer module

The patch add a CMake module that builds a luzer [1],
a coverage-guided, native Lua fuzzing engine.

Needed for the following commit.

1. https://github.com/ligurio/luzer

Author: ligurio

cmake/BuildLuzer.cmake

@@ -0,0 +1,48 @@
+macro(build_luzer)
+  set(LUZER_DIR ${PROJECT_BINARY_DIR}/luzer)
+  set(LUZER_BUILD_DIR ${LUZER_DIR}/build)
+  set(LUZER_LIBRARY_PATH ${LUZER_BUILD_DIR}/luzer)
+  list(APPEND LUZER_LIBRARIES
+      ${LUZER_LIBRARY_PATH}/luzer/luzer.so
+      ${LUZER_LIBRARY_PATH}/luzer/libcustom_mutator.so
+  )
+
+  include(ExternalProject)
+
+  ExternalProject_Add(bundled-luzer
+      GIT_REPOSITORY https://github.com/ligurio/luzer
+      GIT_TAG 649289aa945b7d6c1e2c29edccc83fd3fbe70568
+      GIT_PROGRESS TRUE
+      GIT_SHALLOW FALSE
+      SOURCE_DIR ${LUZER_DIR}/source
+      BINARY_DIR ${LUZER_BUILD_DIR}
+      TMP_DIR ${LUZER_DIR}/tmp
+      STAMP_DIR ${LUZER_DIR}/stamp
+      CONFIGURE_COMMAND
+          ${CMAKE_COMMAND} -B <BINARY_DIR> -S <SOURCE_DIR>
+              -G ${CMAKE_GENERATOR} ${BENCHMARK_CMAKE_FLAGS}
+              -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
+              -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
+      BUILD_COMMAND cd <BINARY_DIR> && ${CMAKE_MAKE_PROGRAM}
+      INSTALL_COMMAND ""
+      CMAKE_GENERATOR ${CMAKE_GENERATOR}
+      BUILD_BYPRODUCTS ${LUZER_LIBRARIES}
+      DOWNLOAD_EXTRACT_TIMESTAMP TRUE
+  )
+
+  add_library(luzer-library STATIC IMPORTED GLOBAL)
+  set_target_properties(luzer-library PROPERTIES
+    IMPORTED_LOCATION "${LUZER_LIBRARIES}")
+  add_dependencies(luzer-library bundled-luzer)
+
+  set(LUZER_LUA_PATH ${LUZER_DIR}/source/?/init.lua)
+  set(LUZER_LUA_PATH ${LUZER_LUA_PATH} PARENT_SCOPE)
+
+  set(LUZER_LUA_CPATH ${LUZER_LIBRARY_PATH}/?${CMAKE_SHARED_LIBRARY_SUFFIX})
+  set(LUZER_LUA_CPATH ${LUZER_LUA_CPATH} PARENT_SCOPE)
+
+  set(LUZER_LIBRARY luzer-library PARENT_SCOPE)
+
+  unset(LUZER_DIR)
+  unset(LUZER_BUILD_DIR)
+endmacro(build_luzer)