LoongArch: Fix the infinite loop caused by calling undefweak symbol

The undefweak symbol value of non-default visibility is 0 and does
not use plt entry, and will not be relocated in the relocate_secion
function. As a result, an infinite loop is generated because
bl %plt(sym) => bl 0.

Fix this by converting the call into a jump address 0.
4 files changed