[vector] Fix build failures

[Qi Feng]

Hi,

This patch fixes zero variant build failure. The failure is caused by
signature mismatch of function SharedRuntime::vector_calling_convention.

Another failure that occurs when building with gcc8 is fixed. The error
message in this case is:

  builds/panama/temp2/hotspot/variant-server/libjvm/objs/vectorIntrinsics.o: In function `LibraryCallKit::inline_vector_mem_operation(bool)':
  repos/panama/src/hotspot/share/opto/vectorIntrinsics.cpp:580: undefined reference to `LibraryCallKit::make_unsafe_address(Node*&, Node*, unsigned long, BasicType, bool)'
  builds/panama/temp2/hotspot/variant-server/libjvm/objs/vectorIntrinsics.o: In function `LibraryCallKit::inline_vector_gather_scatter(bool)':
  repos/panama/src/hotspot/share/opto/vectorIntrinsics.cpp:742: undefined reference to `LibraryCallKit::make_unsafe_address(Node*&, Node*, unsigned long, BasicType, bool)'
  collect2: error: ld returned 1 exit status
  lib/CompileJvm.gmk:181: recipe for target '/home/qifen01/builds/panama/temp2/support/modules_libs/java.base/server/libjvm.so' failed
  make[3]: *** [/home/qifen01/builds/panama/temp2/support/modules_libs/java.base/server/libjvm.so] Error 1

Still another build failure on aarch64, which is caused by the
duplication of instruct vmul8B/vmul16B and introduced in a recent
merge, is fixed as well.

Webrev: http://cr.openjdk.java.net/~qfeng/panama/vectorapi/zero_build/webrev.00/

Thanks,
Qi