Fix optSwitchConvert (#92249)

Co-authored-by: Egor <egorbo@Egors-MacBook-Pro.local>

src/coreclr/jit/switchrecognition.cpp

@@ -289,8 +289,11 @@ bool Compiler::optSwitchConvert(BasicBlock* firstBlock, int testsCount, ssize_t*
  maxValue = newMaxValue;
  }
 
- assert(testIdx <= testsCount);
- if (testIdx < SWITCH_MIN_TESTS)
+ // testIdx is now representing the index of last good test value,
+ // Update testsCount as it's now potentially smaller than initially.
+ testsCount = testIdx;
+
+ if (testsCount < SWITCH_MIN_TESTS)
  {
  // Make sure we still have at least SWITCH_MIN_TESTS values after we filtered out some of them
  return false;
@@ -304,7 +307,7 @@ bool Compiler::optSwitchConvert(BasicBlock* firstBlock, int testsCount, ssize_t*
 
  // Find the last block in the chain
  const BasicBlock* lastBlock = firstBlock;
- for (int i = 0; i < testIdx - 1; i++)
+ for (int i = 0; i < testsCount - 1; i++)
  {
  lastBlock = lastBlock->bbNext;
  }