Avoid unnecessary fp$ in side modules (#2717)

Now that we update the dylink section properly, we can
do the same optimization in side modules as in main ones:
if the module provides a function, don't call an $fp method
during startup, instead add it to the table ourselves and use
the relative offset to the table base.

Fix an issue when the table has no segments initially: the
code just added an offset of 0, but that's not right. Instead,
an a __table_base import and use that as the offset. As
this is ABI-specific I did it on wasm-emscripten-finalize,
leaving TableUtils to just assert on having a singleton
segment.

Add a test of a wasm file with a dylink section to the lld tests.

1 files changed, 0 insertions, 0 deletions

diff --git a/test/lld/shared_add_to_table.wasm b/test/lld/shared_add_to_table.wasm
new file mode 100644
index 000000000..00ea9f906
--- /dev/null
+++ b/test/lld/shared_add_to_table.wasm