[llvm] Reland "[Support]Look up in top-level subcommand as a fallback when looking options for a custom subcommand (PR #71981)

[via llvm-commits]

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git-clang-format --diff 237adfca4ef8d94b7d3d8817da615c5e5897c3da 1a86a5b4493f558b6d4e50aaea46d64539426aa2 -- llvm/lib/Support/CommandLine.cpp llvm/unittests/Support/CommandLineTest.cpp
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diff --git a/llvm/unittests/Support/CommandLineTest.cpp b/llvm/unittests/Support/CommandLineTest.cpp
index b6542363dc61..381fe70b6b48 100644
--- a/llvm/unittests/Support/CommandLineTest.cpp
+++ b/llvm/unittests/Support/CommandLineTest.cpp
@@ -539,7 +539,7 @@ TEST(CommandLineTest, TopLevelOptInSubcommand) {
   // top-level options.  A valid use case is that users of llvm command line
   // tools should be able to specify top-level options defined in any library.
   StackOption<std::string> TopLevelOpt("str", cl::init("txt"),
-                                   cl::desc("A top-level option."));
+                                       cl::desc("A top-level option."));
 
   StackSubCommand SC("sc", "Subcommand");
   StackOption<std::string> PositionalOpt(

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https://github.com/llvm/llvm-project/pull/71981