[WebAssembly] Fix typo in relocation checking

[sbc100]

Summary

Runtime relocation are generated for relocations of type
R_WASM_MEMORY_ADDR_I32 when in PIC mode (either -shared or -pie).

Followup on https://reviews.llvm.org/D60882.

[ruiu]

LGTM

It is a good idea to add a test to catch this though.

[sbc100]

• add test

lld/wasm/InputFiles.cpp

if (Reloc.Type != R_WASM_TYPE_INDEX_LEB) {
     if ((isa<FunctionSymbol>(Sym) || isa<DataSymbol>(Sym)) && !Sym->isLive())
       return 0;
 
     // Special handling for undefined data symbols.  Most relocations against
     // such symbols cannot be resolved.
     if (isa<DataSymbol>(Sym) && Sym->isUndefined()) {
       if (Sym->isWeak() || Config->Relocatable)
         return 0;
-      if (Config->Shared && Reloc.Type == R_WASM_MEMORY_ADDR_I32)
+      // R_WASM_MEMORY_ADDR_I32 relocations in PIC code are turned into runtime
+      // fixups in __wasm_apply_relocs
+      if (Config->Pic && Reloc.Type == R_WASM_MEMORY_ADDR_I32)
         return 0;
       if (Reloc.Type != R_WASM_GLOBAL_INDEX_LEB) {
         llvm_unreachable(
           ("invalid relocation against undefined data symbol: " + toString(*Sym))
               .c_str());
       }
     }
   }