cmd/internal/obj/riscv: fix trampoline calls from large functions
On riscv64, the JAL instruction is only capable of reaching +/-1MB. In the case where
a single function and its trampolines exceeds this size, it is possible that the JAL
is unable to reach the trampoline, which is laid down after the function text. In the
case of large functions, switch back to using a AUIPC+JALR pairs rather than using
trampolines.
Fixes #48791
Change-Id: I119cf3bc20ce4933a9b7ab41a8e514437c6addb9
Reviewed-on: https://go-review.googlesource.com/c/go/+/356250
Trust: Joel Sing <joel@sing.id.au> Reviewed-by: Cherry Mui <cherryyz@google.com>