Bug 1518210 - Wasm: Bounds checking support for x64. r=lth

x86_64 can re-use MacroAssembler-x86-shared for its wasmBoundsCheck, and so it
doesn't require any new assembler code.

It does require a small baseline compiler change to ensure that TlsData is
loaded if we are going to do a bounds check.

I tested this commit with a x64 try run and manually disabling WASM_HUGE_MEMORY.

Differential Revision: https://phabricator.services.mozilla.com/D41863

--HG--
extra : moz-landing-system : lando

js/src/wasm/WasmBaselineCompile.cpp

@@ -5368,11 +5368,11 @@ class BaseCompiler final : public BaseCompilerInterface {
   }
 
   MOZ_MUST_USE bool needTlsForAccess(const AccessCheck& check) {
-#if defined(JS_CODEGEN_ARM) || defined(JS_CODEGEN_MIPS32) || \
-    defined(JS_CODEGEN_MIPS64)
-    return !check.omitBoundsCheck;
-#elif defined(JS_CODEGEN_X86)
+#if defined(JS_CODEGEN_X86)
     return true;
+#elif defined(JS_CODEGEN_ARM) || defined(JS_CODEGEN_MIPS32) || \
+    defined(JS_CODEGEN_MIPS64) || !defined(WASM_HUGE_MEMORY)
+    return !check.omitBoundsCheck;
 #else
     return false;
 #endif

js/src/wasm/WasmTypes.cpp

@@ -34,12 +34,6 @@ using namespace js::wasm;
 using mozilla::IsPowerOfTwo;
 using mozilla::MakeEnumeratedRange;
 
-// We have only tested x64 with WASM_HUGE_MEMORY.
-
-#if defined(JS_CODEGEN_X64) && !defined(WASM_HUGE_MEMORY)
-#  error "Not an expected configuration"
-#endif
-
 // We have only tested WASM_HUGE_MEMORY on x64 and arm64.
 
 #if defined(WASM_HUGE_MEMORY)