[MCA] Don't add a name to the default code region.

This is done in preparation for a patch that fixes PR41523.

llvm-svn: 360243
diff --git a/llvm/tools/llvm-mca/CodeRegion.cpp b/llvm/tools/llvm-mca/CodeRegion.cpp
index 6d41922..eb04ea3 100644
--- a/llvm/tools/llvm-mca/CodeRegion.cpp
+++ b/llvm/tools/llvm-mca/CodeRegion.cpp
@@ -18,7 +18,7 @@
 
 CodeRegions::CodeRegions(llvm::SourceMgr &S) : SM(S) {
   // Create a default region for the input code sequence.
-  Regions.emplace_back(make_unique<CodeRegion>("Default", SMLoc()));
+  Regions.emplace_back(make_unique<CodeRegion>("", SMLoc()));
 }
 
 bool CodeRegion::isLocInRange(SMLoc Loc) const {
diff --git a/llvm/tools/llvm-mca/CodeRegion.h b/llvm/tools/llvm-mca/CodeRegion.h
index cc474b7..80532e3 100644
--- a/llvm/tools/llvm-mca/CodeRegion.h
+++ b/llvm/tools/llvm-mca/CodeRegion.h
@@ -90,6 +90,8 @@
   CodeRegions &operator=(const CodeRegions &) = delete;
 
 public:
+  CodeRegions(llvm::SourceMgr &S);
+
   typedef std::vector<UniqueCodeRegion>::iterator iterator;
   typedef std::vector<UniqueCodeRegion>::const_iterator const_iterator;
 
@@ -103,8 +105,6 @@
   void addInstruction(const llvm::MCInst &Instruction);
   llvm::SourceMgr &getSourceMgr() const { return SM; }
 
-  CodeRegions(llvm::SourceMgr &S);
-
   llvm::ArrayRef<llvm::MCInst> getInstructionSequence(unsigned Idx) const {
     return Regions[Idx]->getInstructions();
   }
diff --git a/llvm/tools/llvm-mca/CodeRegionGenerator.cpp b/llvm/tools/llvm-mca/CodeRegionGenerator.cpp
index 4660af2..14b470a 100644
--- a/llvm/tools/llvm-mca/CodeRegionGenerator.cpp
+++ b/llvm/tools/llvm-mca/CodeRegionGenerator.cpp
@@ -115,7 +115,6 @@
   MCACommentConsumer CC(Regions);
   Lexer.setCommentConsumer(&CC);
 
-  // Create a target-specific parser and perform the parse.
   std::unique_ptr<MCTargetAsmParser> TAP(
       TheTarget.createMCAsmParser(STI, *Parser, MCII, Opts));
   if (!TAP)
@@ -125,7 +124,7 @@
   Parser->setTargetParser(*TAP);
   Parser->Run(false);
 
-  // Get the assembler dialect from the input.  llvm-mca will use this as the
+  // Set the assembler dialect from the input. llvm-mca will use this as the
   // default dialect when printing reports.
   AssemblerDialect = Parser->getAssemblerDialect();
   return Regions;