[Profiler] Simplify CounterExpr

This class is more or less just duplicating LLVM's
`Counter` class, as such we can just wrap it
directly and avoid having to construct it later.
This is a tentative fix for rdar://118185163 since
it eliminates the code in question, though I still
want to investigate that issue further.

Author: hamishknight

include/swift/SIL/SILCoverageMap.h

@@ -162,7 +162,16 @@ class SILCoverageMap : public llvm::ilist_node<SILCoverageMap>,
     return Expressions;
   }
 
-  void printCounter(llvm::raw_ostream &OS, llvm::coverage::Counter C) const;
+  /// Print a given profiling counter expression, given the reference to the
+  /// counter, and the list of counters it may reference.
+  static void
+  printCounter(llvm::raw_ostream &OS, llvm::coverage::Counter C,
+               ArrayRef<llvm::coverage::CounterExpression> Expressions);
+
+  /// Print a given profiling counter expression.
+  void printCounter(llvm::raw_ostream &OS, llvm::coverage::Counter C) const {
+    printCounter(OS, C, getExpressions());
+  }
 
   /// Print the coverage map.
   void print(llvm::raw_ostream &OS, bool Verbose = false,

lib/SIL/IR/SILCoverageMap.cpp

@@ -100,7 +100,8 @@ struct Printer {
 };
 } // end anonymous namespace
 
-void SILCoverageMap::printCounter(llvm::raw_ostream &OS,
-                                  llvm::coverage::Counter C) const {
-  OS << Printer(C, getExpressions());
+void SILCoverageMap::printCounter(
+    llvm::raw_ostream &OS, llvm::coverage::Counter C,
+    ArrayRef<llvm::coverage::CounterExpression> Expressions) {
+  OS << Printer(C, Expressions);
 }