wasm-emscripten-finalize: Do not skip the start function body (#3714)

When we can skip function bodies, we still need to parse the start function
for the pthreads case, see details in the comments. This still gives us 99%
of the speedup as the start function is just 1 function and it's not that big,
so with this we return to full speed after the reversion in #3705

1 files changed, 0 insertions, 0 deletions

diff --git a/test/lld/em_asm_pthread.wasm b/test/lld/em_asm_pthread.wasm
new file mode 100644
index 000000000..e2a5d9a71
--- /dev/null
+++ b/test/lld/em_asm_pthread.wasm