Revert "Export std hash template specializations from dylibs (#7618)" (#7635)

This reverts most of commit 1625f5b.
The upstream commit that caused the issue has been reverted.

The change to use "-Bsymbolic" for the DSO is independently useful.

Author: dschuff

src/compiler-support.h

@@ -31,23 +31,4 @@
 #define WASM_BUILTIN_UNREACHABLE __assume(false)
 #endif
 
-// Forces symbols to be exported from libbinaryen dynamic library. Currently
-// we are just using the default flags, causing most of our symbols to have
-// "default" visibility, meaning they can all be used from the tool sources.
-// However a recent libc++ change caused functions declared in namespace std
-// (e.g. hash template specializations) to have hidden visibility, inherited.
-// from the namespece (see https://github.com/llvm/llvm-project/pull/131156).
-// So this macro forces them to be exported. Currently it is only applied to
-// the hash specializations that are defined in libbinaryen and used in the
-// tool code. In the future if we want to compile libbinaryen with
-// -fvisibility-hidden or use a DLL on Windows, we'll need
-// to explicitly annotate everything we want to export. But that's probably
-// only useful if we want external users to link against libbinaryen.so
-// (currently we don't; it's only used to reduce our install size).
-#if defined(__ELF__) || defined(__MACH__)
-#define DLLEXPORT [[gnu::visibility("default")]]
-#else
-#define DLLEXPORT
-#endif
-
 #endif // wasm_compiler_support_h

src/wasm-type-shape.h

@@ -20,7 +20,6 @@
 #include <functional>
 #include <vector>
 
-#include "compiler-support.h"
 #include "wasm-features.h"
 #include "wasm-type.h"
 
@@ -75,7 +74,7 @@ namespace std {
 
 template<> class hash<wasm::RecGroupShape> {
 public:
-  DLLEXPORT size_t operator()(const wasm::RecGroupShape& shape) const;
+  size_t operator()(const wasm::RecGroupShape& shape) const;
 };
 
 } // namespace std

src/wasm-type.h

@@ -25,7 +25,6 @@
 #include <variant>
 #include <vector>
 
-#include "compiler-support.h"
 #include "support/index.h"
 #include "support/name.h"
 #include "support/parent_index_iterator.h"
@@ -1006,35 +1005,35 @@ namespace std {
 
 template<> class hash<wasm::Type> {
 public:
-  DLLEXPORT size_t operator()(const wasm::Type&) const;
+  size_t operator()(const wasm::Type&) const;
 };
 template<> class hash<wasm::Signature> {
 public:
-  DLLEXPORT size_t operator()(const wasm::Signature&) const;
+  size_t operator()(const wasm::Signature&) const;
 };
 template<> class hash<wasm::Continuation> {
 public:
-  DLLEXPORT size_t operator()(const wasm::Continuation&) const;
+  size_t operator()(const wasm::Continuation&) const;
 };
 template<> class hash<wasm::Field> {
 public:
-  DLLEXPORT size_t operator()(const wasm::Field&) const;
+  size_t operator()(const wasm::Field&) const;
 };
 template<> class hash<wasm::Struct> {
 public:
-  DLLEXPORT size_t operator()(const wasm::Struct&) const;
+  size_t operator()(const wasm::Struct&) const;
 };
 template<> class hash<wasm::Array> {
 public:
-  DLLEXPORT size_t operator()(const wasm::Array&) const;
+  size_t operator()(const wasm::Array&) const;
 };
 template<> class hash<wasm::HeapType> {
 public:
-  DLLEXPORT size_t operator()(const wasm::HeapType&) const;
+  size_t operator()(const wasm::HeapType&) const;
 };
 template<> class hash<wasm::RecGroup> {
 public:
-  DLLEXPORT size_t operator()(const wasm::RecGroup&) const;
+  size_t operator()(const wasm::RecGroup&) const;
 };
 
 } // namespace std