ART: Print C1vis lists as [v1,...,vN]

Checker interprets whitespace as a don't-care placeholder, making it
easier to write assertions which test only parts of the output (e.g.
"//CHECK: Add liveness:44" does not test the inputs or any other
attributes apart from "liveness").

However, since the GraphVisualizer prints lists with elements
separated by spaces ("[ v1 ... vN ]"), this allows for false positives
caused by an occurrence elsewhere in the output. For example, the
assertion: "//CHECK: [ x y ]" will match "[ x y ]" but also
"[ x a y b ]" or even "[ x ] abc [ y ]".

Switching to comma-separated lists works around this issue.

This patch updates all test files, fixes one false positive that this
change revealed (test 442, line 337) and two occurrences of a wrong
match (test 462, lines 121, 149).

Bug: 21189305
Change-Id: I3b22503be3d92529dac0b13f66bccbcfabea6721
diff --git a/compiler/optimizing/graph_visualizer.cc b/compiler/optimizing/graph_visualizer.cc
index e0a9c6f..7ea1240 100644
--- a/compiler/optimizing/graph_visualizer.cc
+++ b/compiler/optimizing/graph_visualizer.cc
@@ -58,7 +58,7 @@
     if (is_empty_) {
       is_empty_ = false;
     } else {
-      sstream_ << " ";
+      sstream_ << ",";
     }
     return sstream_;
   }
@@ -71,7 +71,7 @@
 };
 
 std::ostream& operator<<(std::ostream& os, const StringList& list) {
-  return os << "[ " << list.sstream_.str() << " ]";
+  return os << "[" << list.sstream_.str() << "]";
 }
 
 /**