Fix some portability and build problems (#89)

Remove use of deprecated std::iterator.
Fix colordiff use in clang_format script (from jacob.bramley@arm.com).
Remove debugger tests from non-simulator builds.
Update code coverage record.
diff --git a/src/invalset-vixl.h b/src/invalset-vixl.h
index 40ba507..cf8c982 100644
--- a/src/invalset-vixl.h
+++ b/src/invalset-vixl.h
@@ -243,10 +243,13 @@
 
 
 template <class S>
-class InvalSetIterator
-    : public std::iterator<  // NOLINT(clang-diagnostic-deprecated-declarations)
-          std::forward_iterator_tag,
-          typename S::_ElementType> {
+class InvalSetIterator {
+  using iterator_category = std::forward_iterator_tag;
+  using value_type = typename S::_ElementType;
+  using difference_type = std::ptrdiff_t;
+  using pointer = S*;
+  using reference = S&;
+
  private:
   // Redefine types to mirror the associated set types.
   typedef typename S::_ElementType ElementType;
diff --git a/test/aarch64/test-debugger-aarch64.cc b/test/aarch64/test-debugger-aarch64.cc
index f967335..4fb5df0 100644
--- a/test/aarch64/test-debugger-aarch64.cc
+++ b/test/aarch64/test-debugger-aarch64.cc
@@ -29,6 +29,9 @@
 namespace vixl {
 namespace aarch64 {
 
+#ifdef VIXL_INCLUDE_SIMULATOR_AARCH64
+// The debugger is only available to be tested in simulator builds.
+
 TEST(breakpoints_invalid) {
   SETUP();
 
@@ -359,6 +362,7 @@
   CHECK_OUTPUT();
 }
 
+#endif  // VIXL_INCLUDE_SIMULATOR_AARCH64
 
 }  // namespace aarch64
 }  // namespace vixl
diff --git a/tools/clang_format.py b/tools/clang_format.py
index 2a08180..a9c53c9 100755
--- a/tools/clang_format.py
+++ b/tools/clang_format.py
@@ -128,10 +128,11 @@
             stdin = p_diff.stdout,
             stdout = subprocess.PIPE, stderr = subprocess.STDOUT)
     out, unused = p_colordiff.communicate()
+    rc += p_colordiff.returncode
   else:
     out, unused = p_diff.communicate()
+    rc += p_diff.returncode
 
-  rc += p_diff.returncode
 
   if in_place:
       cmd_format = [clang_format, '-i', filename]
diff --git a/tools/code_coverage.log b/tools/code_coverage.log
index 3bd0590..c27ab83 100644
--- a/tools/code_coverage.log
+++ b/tools/code_coverage.log
@@ -21,3 +21,4 @@
 1686666000 82.90% 97.57% 94.87%
 1693487542 82.91% 97.57% 94.87%
 1702052331 82.89% 97.59% 94.77%
+1707395574 82.89% 97.59% 94.77%