cmd/compile: don't merge symbols on riscv64 when dynamic linking
Each plugin is compiled as a separate shared object,
with its own symbol table. When dynamic linking plugin symbols
are resolved within the plugin's scope, not globally merged to
avoid conflicts.
Change-Id: I9e6986085855c17fbd6c39b937cb6129d216f5e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/435015
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Joel Sing <joel@sing.id.au> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com>