[lld] [lld][WebAssembly] Allow linker-synthetic symbols to be undefined when building shared libraries (PR #128223)

[YAMAMOTO Takashi via llvm-commits]

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@@ -965,6 +965,8 @@ static void createSyntheticSymbols() {
   } else {
     // For non-PIC code
     WasmSym::stackPointer = createGlobalVariable("__stack_pointer", true);
+    WasmSym::definedMemoryBase = symtab->addOptionalDataSymbol("__memory_base");
+    WasmSym::definedTableBase = symtab->addOptionalDataSymbol("__table_base");
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yamt wrote:

these calls seem too early in the link process.
the symbol table is almost empty here and they are effectively no-op i guess.
createSyntheticSymbols is called even before addFile.


https://github.com/llvm/llvm-project/pull/128223