Reland "Make compiler/optimizing/ symbols hidden."
This reverts commit 0a51605ddd81635135463dab08b6f7c21b58ffb0.
Reason for revert: Reland after some of the required work
was merged in other CLs.
Also address a TODO from the original CL to mark required
symbols with EXPORT in `intrinsic_objects.h`.
Also mark symbols in new files as HIDDEN.
Bug: 186902856
Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Change-Id: I936d448983928af23614ca82c2d0bf9a645e2c52
diff --git a/compiler/optimizing/nodes_vector.h b/compiler/optimizing/nodes_vector.h
index a2cd86d..73f6c40 100644
--- a/compiler/optimizing/nodes_vector.h
+++ b/compiler/optimizing/nodes_vector.h
@@ -21,7 +21,7 @@
// is included in the header file nodes.h itself. However it gives editing tools better context.
#include "nodes.h"
-namespace art {
+namespace art HIDDEN {
// Memory alignment, represented as an offset relative to a base, where 0 <= offset < base,
// and base is a power of two. For example, the value Alignment(16, 0) means memory is