ART: Clean up test exec code

Add a helper for fork+exec of another program and collection of
that process' output. Use the helper in other code.

Clean up some tests. Move away from global #ifdef ARCH and
disable tests with the usual-style macros so that it's easier
to see refactoring issues immediately.

Test: mmma
Test: m test-art-host
Change-Id: Ic450e8a3bb24fc6fe423c0e1e007eb0bb34e22b4
diff --git a/runtime/common_runtime_test.h b/runtime/common_runtime_test.h
index d21973e..234b66a 100644
--- a/runtime/common_runtime_test.h
+++ b/runtime/common_runtime_test.h
@@ -191,12 +191,30 @@
   DISALLOW_COPY_AND_ASSIGN(CheckJniAbortCatcher);
 };
 
+#define TEST_DISABLED_FOR_ARM() \
+  if (kRuntimeISA == InstructionSet::kArm || kRuntimeISA == InstructionSet::kThumb2) { \
+    printf("WARNING: TEST DISABLED FOR ARM\n"); \
+    return; \
+  }
+
+#define TEST_DISABLED_FOR_ARM64() \
+  if (kRuntimeISA == InstructionSet::kArm64) { \
+    printf("WARNING: TEST DISABLED FOR ARM64\n"); \
+    return; \
+  }
+
 #define TEST_DISABLED_FOR_MIPS() \
   if (kRuntimeISA == InstructionSet::kMips) { \
     printf("WARNING: TEST DISABLED FOR MIPS\n"); \
     return; \
   }
 
+#define TEST_DISABLED_FOR_MIPS64() \
+  if (kRuntimeISA == InstructionSet::kMips64) { \
+    printf("WARNING: TEST DISABLED FOR MIPS64\n"); \
+    return; \
+  }
+
 #define TEST_DISABLED_FOR_X86() \
   if (kRuntimeISA == InstructionSet::kX86) { \
     printf("WARNING: TEST DISABLED FOR X86\n"); \