add ARROW_USE_COVERAGE

cpp/cmake_modules/san-config.cmake

@@ -87,6 +87,16 @@ if (${ARROW_USE_TSAN})
 endif()
 
 
+if (${ARROW_USE_COVERAGE})
+  if(NOT ("${COMPILER_FAMILY}" STREQUAL "clang"))
+    message(SEND_ERROR "You can only enable coverage with clang")
+  endif()
+  add_definitions("-fsanitize-coverage=trace-pc-guard")
+
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize-coverage=trace-pc-guard")
+endif()
+
+
 if ("${ARROW_USE_UBSAN}" OR "${ARROW_USE_ASAN}" OR "${ARROW_USE_TSAN}")
   # GCC 4.8 and 4.9 (latest as of this writing) don't allow you to specify a
   # sanitizer blacklist.