Changes

Modify default nodeCountThreshold value used by inliner

This commit changes the default value of nodeCountThreshold used
by the inliner from 16000 to 3000. The change will only be performed
when the `Options::TR_NotCompileTimeSensitive` flag is set to `false`
(which is the default value). Note that the OpenJ9 downstream project
sets this flag to `true` for:

(1) Compilations at hot (and above) opt level
(2) AOT compilations
(3) Compilations under -Xtune:throughput mode (OpenJ9 specific)
(4) Compilations before checkpoint when CRIU is used (OpenJ9 specific)

In all those cases mentioned above, the original (16000) threshold will
be used.

This change is supposed to reduce the amount of inlining done in very
large methods and therefore reduce JIT compilation overhead.

To override the value chosen by the JIT you can use the
TR_NodeCountThreshold=<NNN> environment variable.

Signed-off-by: Marius <mpirvu@ca.ibm.com>
 (commit: e07e8df)