Remove unused VariableLocation::GLOBAL.

src/ast/prettyprinter.cc

Index: src/ast/prettyprinter.cc
diff --git a/src/ast/prettyprinter.cc b/src/ast/prettyprinter.cc
index f19ee23de13f646240a99594fc0a2546c7ab1b34..a411b7066af3cfdb3b9e471506ab13ad7ea246f0 100644
--- a/src/ast/prettyprinter.cc
+++ b/src/ast/prettyprinter.cc
@@ -1028,9 +1028,6 @@ void AstPrinter::VisitVariableProxy(VariableProxy* node) {
       case VariableLocation::CONTEXT:
         SNPrintF(buf + pos, " context[%d]", var->index());
         break;
-      case VariableLocation::GLOBAL:
-        SNPrintF(buf + pos, " global[%d]", var->index());
-        break;
       case VariableLocation::LOOKUP:
         SNPrintF(buf + pos, " lookup");
         break;