hg: jdk/sandbox: 8233590: Compiler thread creation fails with assert(_c2_count > 0 || _c1_count > 0) failed: No compilers?

[chris.hegarty at oracle.com]

Changeset: 358783d2ba0b
Author:    iveresov
Date:      2019-11-05 09:59 -0800
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/358783d2ba0b

8233590: Compiler thread creation fails with assert(_c2_count > 0 || _c1_count > 0) failed: No compilers?
Summary: Handle the case with -XX:-TieredCompilation properly
Reviewed-by: shade, thartmann
Contributed-by: fujie at loongson.cn

! src/hotspot/share/runtime/flags/jvmFlagConstraintsCompiler.cpp