[java-decompiler] skips illegal local variable names

testData/results/TestIllegalVarName.dec

@@ -0,0 +1,33 @@
+package pkg;
+
+import kotlin.Metadata;
+import kotlin.jvm.internal.Intrinsics;
+import org.jetbrains.annotations.NotNull;
+
+@Metadata(
+   mv = {1, 1, 0},
+   bv = {1, 0, 0},
+   k = 1,
+   d1 = {"\u0000\u001a\n\u0002\u0018\u0002\n\u0002\u0010\u0000\n\u0002\b\u0002\n\u0002\u0010\u000e\n\u0002\b\u0002\n\u0002\u0010\b\n\u0000\u0018\u00002\u00020\u0001B\u0005¢\u0006\u0002\u0010\u0002J\u0016\u0010\u0003\u001a\u00020\u00042\u0006\u0010\u0005\u001a\u00020\u00042\u0006\u0010\u0006\u001a\u00020\u0007¨\u0006\b"},
+   d2 = {"Lpkg/TestIllegalVarName;", "", "()V", "m", "", "this", "enum", "", "java-decompiler-plugin"}
+)
+public final class TestIllegalVarName {
+   @NotNull
+   public final String m(@NotNull String var1, int var2) {
+      Intrinsics.checkParameterIsNotNull(var1, "this");
+      return var1 + '/' + var2;// 5
+   }
+}
+
+class 'pkg/TestIllegalVarName' {
+   method 'm (Ljava/lang/String;I)Ljava/lang/String;' {
+      1      16
+      3      16
+      11      17
+      1a      17
+      1d      17
+   }
+}
+
+Lines mapping:
+5 <-> 18

testData/src/pkg/TestIllegalVarName.kt

@@ -0,0 +1,7 @@
+package pkg
+
+class TestIllegalVarName {
+  fun m(`this`: String, `enum`: Int): String {
+    return `this` + '/' + `enum`
+  }
+}