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/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index 7d78d75..ac212e0 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -31,7 +31,7 @@
#include "sharpening.h"
#include "string_builder_append.h"
-namespace art {
+namespace art HIDDEN {
// Whether to run an exhaustive test of individual HInstructions cloning when each instruction
// is replaced with its copy if it is clonable.