more generous Java memory, also hoping to prevent spurious java.lang.StackOverflowError in isabelle_cronjob;

--- a/etc/settings	Thu Apr 23 09:57:41 2020 +0200
+++ b/etc/settings	Thu Apr 23 12:03:16 2020 +0200
@@ -14,9 +14,9 @@
 
 ISABELLE_JAVA_SYSTEM_OPTIONS="-server -Dfile.encoding=UTF-8 -Disabelle.threads=0 -Djdk.gtk.version=2.2"
 
-ISABELLE_TOOL_JAVA_OPTIONS="-Djava.awt.headless=true -Xms512m -Xmx2560m -Xss16m"
+ISABELLE_TOOL_JAVA_OPTIONS="-Djava.awt.headless=true -Xms512m -Xmx4g -Xss32m"
 
-ISABELLE_SCALAC_OPTIONS="-encoding UTF-8 -nowarn -target:jvm-1.8 -Xmax-classfile-name 130 -J-Xms512m -J-Xmx2560m -J-Xss16m"
+ISABELLE_SCALAC_OPTIONS="-encoding UTF-8 -nowarn -target:jvm-1.8 -Xmax-classfile-name 130 -J-Xms512m -J-Xmx4g -J-Xss32m"
 
 classpath "$ISABELLE_HOME/lib/classes/Pure.jar"
 

--- a/src/Tools/jEdit/etc/settings	Thu Apr 23 09:57:41 2020 +0200
+++ b/src/Tools/jEdit/etc/settings	Thu Apr 23 12:03:16 2020 +0200
@@ -5,7 +5,7 @@
 
 JEDIT_OPTIONS="-reuseview -nobackground -nosplash -log=9"
 
-JEDIT_JAVA_OPTIONS="-Xms512m -Xmx2560m -Xss8m"
+JEDIT_JAVA_OPTIONS="-Xms512m -Xmx4g -Xss32m"
 JEDIT_JAVA_SYSTEM_OPTIONS="-Duser.language=en -Dawt.useSystemAAFontSettings=on -Dswing.aatext=true -Dapple.laf.useScreenMenuBar=true -Dapple.awt.application.name=Isabelle"
 
 ISABELLE_JEDIT_OPTIONS=""