cmake: fix code coverage module

- Add `LUA_SOURCE_DIR` to BuildLuaJIT.cmake, becuase it is used
  in CodeCoverage.cmake.
- Fix deprecated gcovr options: `--branches` [1] and
  `--sort-percentage` [2].

1. https://gcovr.com/en/stable/manpage.html#cmdoption-gcovr-b
2. https://gcovr.com/en/stable/manpage.html#cmdoption-gcovr-p

Author: ligurio

cmake/BuildLuaJIT.cmake

@@ -130,6 +130,7 @@ macro(build_luajit LJ_VERSION)
     set(LUA_LIBRARIES bundled-liblua)
     set(LUA_INCLUDE_DIR ${LJ_SOURCE_DIR}/src/)
     set(LUA_VERSION_STRING "LuaJIT ${LJ_VERSION}")
+    set(LUA_SOURCE_DIR ${LJ_SOURCE_DIR})
 
     unset(LJ_SOURCE_DIR)
     unset(LJ_BINARY_DIR)

cmake/CodeCoverage.cmake

@@ -18,7 +18,7 @@ endif()
 
 # See https://gcovr.com/en/stable/manpage.html.
 set(GCOVR_OPTIONS
-  --branches
+  --txt-metric branch
   --cobertura ${COVERAGE_XML_REPORT}
   --decisions
   --gcov-executable "llvm-cov gcov"
@@ -29,7 +29,7 @@ set(GCOVR_OPTIONS
   --output ${COVERAGE_HTML_REPORT}
   --print-summary
   --root ${LUA_SOURCE_DIR}
-  --sort-percentage
+  --sort-key uncovered-percent
 )
 
 if(USE_LUA)