add more missing TruffleBoundaries for JDK15

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/bytes/BytesBuiltins.java

@@ -126,6 +126,7 @@
 import com.oracle.graal.python.util.PythonUtils;
 import com.oracle.truffle.api.CompilerAsserts;
 import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.CachedContext;
 import com.oracle.truffle.api.dsl.Fallback;
@@ -2021,6 +2022,7 @@ public static ExpectIntNode createExpectIntNode() {
         }
 
         @Override
+        @TruffleBoundary
         protected List<byte[]> splitWhitespace(byte[] bytes, int len, int maxsplit) {
             int i, j, maxcount = maxsplit;
             List<byte[]> list = new ArrayList<>();

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/traceback/TracebackBuiltins.java

@@ -81,7 +81,7 @@ public Object dir(@SuppressWarnings("unused") PTraceback self) {
     /**
      * Use the Truffle stacktrace attached to an exception to populate the information in the
      * {@link PTraceback} and its tb_next chain as far as the stacktrace goes for this segment.
-     * 
+     *
      * @see GetTracebackNode
      */
     abstract static class MaterializeTruffleStacktraceNode extends Node {
@@ -91,6 +91,7 @@ abstract static class MaterializeTruffleStacktraceNode extends Node {
         void doExisting(@SuppressWarnings("unused") PTraceback tb) {
         }
 
+        @TruffleBoundary
         @Specialization(guards = "!tb.isMaterialized()")
         void doMaterialize(PTraceback tb,
                         @Cached MaterializeFrameNode materializeFrameNode,

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/literal/FormatStringLiteralNode.java

@@ -123,7 +123,7 @@ public Object execute(VirtualFrame frame) {
             PythonUtils.getChars(value, 0, value.length(), result, nextIndex);
             nextIndex += value.length();
         }
-        return new String(result);
+        return PythonUtils.newString(result);
     }
 
     private void ensureCastNodes() {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/util/PythonUtils.java

@@ -150,6 +150,11 @@ public static RootCallTarget getOrCreateCallTarget(RootNode rootNode) {
         return ct;
     }
 
+    @TruffleBoundary(allowInlining = true)
+    public static String newString(char[] chars) {
+        return new String(chars);
+    }
+
     @TruffleBoundary(allowInlining = true)
     public static StringBuilder newStringBuilder() {
         return new StringBuilder();