deps: Add Luajit compilation flags to improve debugging

test/functional/helpers.lua

@@ -1,8 +1,3 @@
-if jit then
-  -- Disable JIT because of random errors on Travis with OS X.
-  jit.off(true, true)
-end
-
 require('coxpcall')
 local Loop = require('nvim.loop')
 local MsgpackStream = require('nvim.msgpack_stream')

third-party/CMakeLists.txt

@@ -202,6 +202,10 @@ if(USE_BUNDLED_LUAJIT)
     INSTALL_COMMAND ${MAKE_PRG} CC=${DEPS_C_COMPILER}
                                 PREFIX=${DEPS_INSTALL_DIR}
                                 CFLAGS=-fPIC
+                                CFLAGS+=-DLUAJIT_DISABLE_JIT
+                                CFLAGS+=-DLUA_USE_APICHECK
+                                CFLAGS+=-DLUA_USE_ASSERT
+                                CCDEBUG+=-g
                                 BUILDMODE=static
                                 install)
   list(APPEND THIRD_PARTY_DEPS luajit)