Bug 1279312 - Use TLS pointer for the stack limit check. r=luke

Get the stack limit from TlsData::stackLimit instead of
SymbolicAddress::StackLimit. Since the TLS pointer register is available at
every function prologue, the over-recursion check is the same cost as using the
statically linked address.

js/src/jit/CodeGenerator.cpp

@@ -8983,8 +8983,10 @@ CodeGenerator::generateWasm(wasm::SigIdDesc sigId, wasm::FuncOffsets* offsets)
     // pushing framePushed to catch cases with really large frames.
     Label onOverflow;
     if (!omitOverRecursedCheck()) {
+        // Get the per-thread stack limit from the TlsData struct pointed
+        // to by the WasmTlsReg hidden argument register.
         masm.branchPtr(Assembler::AboveOrEqual,
-                       wasm::SymbolicAddress::StackLimit,
+                       Address(WasmTlsReg, offsetof(wasm::TlsData, stackLimit)),
                        masm.getStackPointer(),
                        &onOverflow);
     }