hg: jdk/sandbox: Merge

[michael.x.mcmahon at oracle.com]

Changeset: 00a62a654411
Author:    michaelm
Date:      2020-02-24 10:54 +0000
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/00a62a654411

Merge

- make/autoconf/basics.m4
- make/autoconf/basics_windows.m4
! make/autoconf/flags.m4
! make/autoconf/toolchain.m4
! src/hotspot/os/linux/os_linux.cpp
! src/hotspot/share/runtime/thread.cpp
! src/hotspot/share/runtime/thread.hpp