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/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 72ca927..4092858 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -57,7 +57,7 @@
#error "ARM64 Codegen VIXL macro-assembler macro already defined."
#endif
-namespace art {
+namespace art HIDDEN {
template<class MirrorType>
class GcRoot;