ART: Make InstructionSet an enum class and add kLast.

Adding InstructionSet::kLast shall make it easier to encode
the InstructionSet in fewer bits using BitField<>. However,
introducing `kLast` into the `art` namespace is not a good
idea, so we change the InstructionSet to an enum class.
This also uncovered a case of InstructionSet::kNone being
erroneously used instead of vixl32::Condition::None(), so
it's good to remove `kNone` from the `art` namespace.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Change-Id: I6fa6168dfba4ed6da86d021a69c80224f09997a6

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/exception_test.cc b/compiler/exception_test.cc
index b434e90f0d..897b50bdac 100644
--- a/compiler/exception_test.cc
+++ b/compiler/exception_test.cc
@@ -98,7 +98,7 @@ class ExceptionTest : public CommonRuntimeTest {
              static_cast<const void*>(fake_header_code_and_maps_.data() +
                                           (fake_header_code_and_maps_.size() - code_size)));
 
-    if (kRuntimeISA == kArm) {
+    if (kRuntimeISA == InstructionSet::kArm) {
       // Check that the Thumb2 adjustment will be a NOP, see EntryPointToCodePointer().
       CHECK_ALIGNED(stack_maps_offset, 2);
     }