[llvm] [Profile] Add a more descriptive message to the bad_header error (PR #211281)

[Hubert Tong via llvm-commits]

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@@ -513,7 +513,8 @@ Error RawInstrProfReader<IntPtrT>::readHeader() {
   if (!hasFormat(*DataBuffer))
     return error(instrprof_error::bad_magic);
   if (DataBuffer->getBufferSize() < sizeof(RawInstrProf::Header))
-    return error(instrprof_error::bad_header);
+    return error(instrprof_error::bad_header,
+                 std::string("Profile file header is truncated"));
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hubert-reinterpretcast wrote:

Nit: Follow https://llvm.org/docs/CodingStandards.html#error-and-warning-messages

https://github.com/llvm/llvm-project/pull/211281