Revert "Revert "Upgrade to 5.0.71.48"" DO NOT MERGE

This reverts commit f2e3994fa5148cc3d9946666f0b0596290192b0e,
and updates the x64 makefile properly so it doesn't break that
build.

FPIIM-449

Change-Id: Ib83e35bfbae6af627451c926a9650ec57c045605
(cherry picked from commit 109988c7ccb6f3fd1a58574fa3dfb88beaef6632)
diff --git a/src/regexp/regexp-ast.cc b/src/regexp/regexp-ast.cc
index 31c93b1..b5c2bb6 100644
--- a/src/regexp/regexp-ast.cc
+++ b/src/regexp/regexp-ast.cc
@@ -172,9 +172,9 @@
 
 
 void RegExpUnparser::VisitCharacterRange(CharacterRange that) {
-  os_ << AsUC16(that.from());
+  os_ << AsUC32(that.from());
   if (!that.IsSingleton()) {
-    os_ << "-" << AsUC16(that.to());
+    os_ << "-" << AsUC32(that.to());
   }
 }