RFR: 8220049: Remove -XX:-ThreadLocalHandshakes

[Robbin Ehn]

Hi all, please review,

ThreadLocalHandshakes is obsolete in JDK 14 and this changeset removes the flag.
All platforms except arm32 uses local poll.
(after https://bugs.openjdk.java.net/browse/JDK-8235410, Enable handshakes on Linux x86 (32-bit)
, which this patch goes on top of)
When arm32 also have local poll we remove the global poll code.

Changeset:
http://cr.openjdk.java.net/~rehn/8220049/v1/webrev/
Issue:
https://bugs.openjdk.java.net/browse/JDK-8220049

Passes t1-7, built arm32, aarch64, sparc-solaris, linux x86/x64, windows x64, osx, linux s390x, linux ppc64le

(note that on x86 there is missníng include in src/hotspot/cpu/x86/sharedRuntime_x86_32.cpp,
--- a/src/hotspot/cpu/x86/sharedRuntime_x86_32.cpp      Tue Dec 10 08:47:38 2019 +0100
+++ b/src/hotspot/cpu/x86/sharedRuntime_x86_32.cpp      Tue Dec 10 10:24:14 2019 +0100
@@ -32,0 +33,1 @@
+#include "gc/shared/barrierSetAssembler_x86.hpp"
)

Martin please have a look on aix changes.

Thanks, Robbin