[nfc][llvm-profdata] Use cl::Subcommand to organize subcommand and options in llvm-profdata

llvm/lib/Support/CommandLine.cpp

@@ -1667,6 +1667,13 @@ bool CommandLineParser::ParseCommandLineOptions(int argc,
       Handler = LookupLongOption(*ChosenSubCommand, ArgName, Value,
                                  LongOptionsUseDoubleDash, HaveDoubleDash);
 
+      // If Handler is not found in a specialized subcommand, look up handler
+      // in the top-level subcommand.
+      // cl::opt without cl::sub belongs to top-level subcommand.
+      if (!Handler && ChosenSubCommand != &SubCommand::getTopLevel())
+        Handler = LookupLongOption(SubCommand::getTopLevel(), ArgName, Value,
+                                   LongOptionsUseDoubleDash, HaveDoubleDash);
+
       // Check to see if this "option" is really a prefixed or grouped argument.
       if (!Handler && !(LongOptionsUseDoubleDash && HaveDoubleDash))
         Handler = HandlePrefixedOrGroupedOption(ArgName, Value, ErrorParsing,

llvm/test/tools/llvm-profdata/errors.test

@@ -5,4 +5,4 @@ RUN: not llvm-profdata show file -o file 2>&1 | FileCheck %s --check-prefix SHOW
 SHOW-OUT: Input file name cannot be the same as the output file name!
 
 RUN: not llvm-profdata 2>&1 | FileCheck %s --check-prefix EMPTY
-EMPTY: No command specified!
+EMPTY: No subcommand specified!

llvm/test/tools/llvm-profdata/version.test

@@ -1,4 +1,3 @@
 # RUN: llvm-profdata --version | FileCheck %s
 
-# CHECK: llvm-profdata
 # CHECK: LLVM version {{.*}}