[SILPrinter] Print the debug scope when dumping a block.

<rdar://problem/36524469>

Author: Davide Italiano

lib/SIL/SILPrinter.cpp

@@ -2215,6 +2215,14 @@ void SILBasicBlock::dump() const {
 /// Pretty-print the SILBasicBlock to the designated stream.
 void SILBasicBlock::print(raw_ostream &OS) const {
   SILPrintContext Ctx(OS);
+
+  // Print the debug scope (and compute if we didn't do it already).
+  auto &SM = this->getParent()->getModule().getASTContext().SourceMgr;
+  for (auto &I : *this) {
+    SILPrinter P(Ctx);
+    P.printDebugScope(I.getDebugScope(), SM);
+  }
+
   SILPrinter(Ctx).print(this);
 }