[Interpreter] Fix generate-bytecode-expectations help message.

--pool-type=int and double have now been merged into number.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1717633002

Cr-Commit-Position: refs/heads/master@{#34164}

test/cctest/interpreter/generate-bytecode-expectations.cc

@@ -408,7 +408,7 @@ void PrintUsage(const char* exec_path) {
          "  --output=file.name\n"
          "      Specify the output file. If not specified, output goes to "
          "stdout.\n"
-         "  --pool-type=(int|double|string|mixed)\n"
+         "  --pool-type=(number|string|mixed)\n"
          "      Specify the type of the entries in the constant pool "
          "(default: mixed).\n"
          "\n"