8382628: VectorExpressionFuzzer.java fails due to C1 compilation bailout

Reviewed-by: chagedorn, thartmann

test/hotspot/jtreg/compiler/vectorapi/VectorExpressionFuzzer.java

@@ -41,6 +41,16 @@
 //
 //       A trick to extend this to other platforms: create a new run block, so you have full
 //       freedom to restrict it as necessary for platform and vector features.
+//
+// TODO: Some compilation bailouts are to be expected, for example, we've encountered this before:
+//         COMPILE SKIPPED: out of virtual registers in LIR generator (retry at different tier)
+//       Which manifested in:
+//         compiler.lib.ir_framework.shared.TestRunException: <some method> not compilable (anymore) at level C1_FULL_PROFILE. Most likely, this is not expected, but if it is, you can use 'allowNotCompilable'.
+//
+//       It would be good to only selectively allow some bailouts. For now, we just have to do:
+//         @Test(allowNotCompilable = true)
+//       But after JDK-8378943, we should list only the expected bailouts, so that we can
+//       detect and investigate any unexpected bailouts.
 
 package compiler.vectorapi;
 
@@ -127,7 +137,7 @@ public class VectorExpressionFuzzer {
 
                 static final Object $GOLD = $test();
 
-                @Test
+                @Test(allowNotCompilable = true)
                 public static Object $test() {
                     try {
                 """,
@@ -296,7 +306,7 @@ public class VectorExpressionFuzzer {
                 """
                 }
 
-                @Test
+                @Test(allowNotCompilable = true)
                 public static Object $test(
                 """,
                 receiveArguments,