RFR 8244105: JDK 11.0.7 -Xlog gc issue with file path if not exist

[Harold Seigel]

Hi,

Please review this fix for JDK-8244105.  The fix continues program 
execution even when specified logging options are invalid.  Previously, 
invalid logging options terminated the program.  Now, a warning is 
issued.  For example:

     > java -Xlog:"gc*:file=/dont/exist" -version
    [0.001s][error][logging] Error opening log file '/dont/exist': No
    such file or directory
    [0.001s][error][logging] Initialization of output 'file=/dont/exist'
    using options '(null)' failed.
    Java HotSpot(TM) 64-Bit Server VM warning: Invalid -Xlog option
    '-Xlog:gc*:file=/dont/exist', see error log for details.

    java version "15-internal" 2020-09-15
    Java(TM) SE Runtime Environment (fastdebug build
    15-internal+0-2020-05-08-1313404.hseigel.bug8244105)
    Java HotSpot(TM) 64-Bit Server VM (fastdebug build
    15-internal+0-2020-05-08-1313404.hseigel.bug8244105, mixed mode,
    sharing)

Open Webrev: 
http://cr.openjdk.java.net/~hseigel/bug_8244105/webrev/index.html

JBS Bug: https://bugs.openjdk.java.net/browse/JDK-8244105

The fix was regression tested by running Mach5 tiers 1 and 2 tests and 
builds on Linux-x64, Solaris, Windows, and Mac OS X and by running Mach5 
tiers 3-5 tests on Linux-x64.

Thanks, Harold