Merge pull request jruby#9054 from headius/min_java_version_in_release_file_9.4

Migrate .java-version contents to .jruby.release (9.4)

Author: headius

bin/.java-version

@@ -1,2 +1,3 @@
 JRUBY_VERSION=9.4.15.0-SNAPSHOT
 JRUBY_MAIN=org.jruby.Main
+JRUBY_MINIMUM_JAVA_VERSION=8

bin/.jruby.release

@@ -555,16 +555,24 @@ if [ -f "$JAVA_HOME/release" ]; then
     esac
 fi
 
-# Default java_runtime_version to $java_version
-: "${java_runtime_version:=$java_version}"
+# Get main class and version from .jruby.release
 
 # shellcheck source=/dev/null
-if [ -f "$JRUBY_HOME/bin/.java-version" ] && . "$JRUBY_HOME/bin/.java-version" && [ "${JRUBY_MINIMUM_JAVA_VERSION-}" ]; then
+# shellcheck disable=2153  # Assigned in sourced file
+if [ -f "$jruby_release_file" ] && . "$jruby_release_file"; then
+    java_class=$JRUBY_MAIN
+    jruby_version=$JRUBY_VERSION
     minimum_java_version=$JRUBY_MINIMUM_JAVA_VERSION
 else
-    # Only 9.4.12.0 and earlier will have shipped without a .java-version file, so fall back on minimum of 8
+    # Only 9.4.14.0 and earlier will have shipped without a .jruby.release file, so fall back on 9.4 defaults
+    java_class=org.jruby.Main
+    jruby_version=unspecified
     minimum_java_version=8
 fi
+
+# Default java_runtime_version to $java_version
+: "${java_runtime_version:=$java_version}"
+
 add_log "Detected Java version: $java_version"
 add_log "Detected Java runtime version: $java_runtime_version"
 
@@ -645,18 +653,6 @@ JAVA_OPTS="$JAVA_OPTS_TEMP"
 
 CP_DELIMITER=":"
 
-# Get main class and version from .jruby.release
-
-# shellcheck source=/dev/null
-# shellcheck disable=2153  # Assigned in sourced file
-if [ -f "$jruby_release_file" ] && . "$jruby_release_file"; then
-    java_class=$JRUBY_MAIN
-    jruby_version=$JRUBY_VERSION
-else
-    java_class=org.jruby.main
-    jruby_version=unspecified
-fi
-
 # Find main jruby jar and add it to the classpath
 jruby_jar=
 for j in "$JRUBY_HOME"/lib/jruby.jar "$JRUBY_HOME"/lib/jruby-complete.jar; do