[WebAssembly] Add WebAssembly::Specifier

Move wasm-specific members outside of MCSymbolRefExpr::VariantKind (a
legacy interface I am eliminating). Most changes are mechanic and
similar to what I've done for many ELF targets (e.g. X86 #132149)

Notes:

* `fixSymbolsInTLSFixups` is replaced with `setTLS` in
  `WebAssemblyWasmObjectWriter::getRelocType`, similar to what I've done
  for many ELF targets.
* `SymA->setUsedInGOT()` in `recordRelocation` is moved to
  `getRelocType`.

While here, rename "Modifier' to "Specifier":

> "Relocation modifier", though concise, suggests adjustments happen during the linker's relocation step rather than the assembler's expression evaluation. I landed on "relocation specifier" as the winner. It's clear, aligns with Arm and IBM’s usage, and fits the assembler's role seamlessly.

Pull Request: https://github.com/llvm/llvm-project/pull/133116

1 files changed, 9 insertions, 8 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
index d78e755..8c86292 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "WebAssemblyMCInstLower.h"
+#include "MCTargetDesc/WebAssemblyMCExpr.h"
 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
 #include "TargetInfo/WebAssemblyTargetInfo.h"
 #include "Utils/WebAssemblyTypeUtilities.h"
@@ -91,32 +92,32 @@ MCSymbol *WebAssemblyMCInstLower::GetExternalSymbolSymbol(
 
 MCOperand WebAssemblyMCInstLower::lowerSymbolOperand(const MachineOperand &MO,
                                                      MCSymbol *Sym) const {
-  MCSymbolRefExpr::VariantKind Kind = MCSymbolRefExpr::VK_None;
+  auto Spec = WebAssembly::S_None;
   unsigned TargetFlags = MO.getTargetFlags();
 
   switch (TargetFlags) {
     case WebAssemblyII::MO_NO_FLAG:
       break;
     case WebAssemblyII::MO_GOT_TLS:
-      Kind = MCSymbolRefExpr::VK_WASM_GOT_TLS;
+      Spec = WebAssembly::S_GOT_TLS;
       break;
     case WebAssemblyII::MO_GOT:
-      Kind = MCSymbolRefExpr::VK_GOT;
+      Spec = WebAssembly::S_GOT;
       break;
     case WebAssemblyII::MO_MEMORY_BASE_REL:
-      Kind = MCSymbolRefExpr::VK_WASM_MBREL;
+      Spec = WebAssembly::S_MBREL;
       break;
     case WebAssemblyII::MO_TLS_BASE_REL:
-      Kind = MCSymbolRefExpr::VK_WASM_TLSREL;
+      Spec = WebAssembly::S_TLSREL;
       break;
     case WebAssemblyII::MO_TABLE_BASE_REL:
-      Kind = MCSymbolRefExpr::VK_WASM_TBREL;
+      Spec = WebAssembly::S_TBREL;
       break;
     default:
       llvm_unreachable("Unknown target flag on GV operand");
   }
 
-  const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Kind, Ctx);
+  const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Spec, Ctx);
 
   if (MO.getOffset() != 0) {
     const auto *WasmSym = cast<MCSymbolWasm>(Sym);
@@ -149,7 +150,7 @@ MCOperand WebAssemblyMCInstLower::lowerTypeIndexOperand(
   WasmSym->setSignature(Signature);
   WasmSym->setType(wasm::WASM_SYMBOL_TYPE_FUNCTION);
   const MCExpr *Expr =
-      MCSymbolRefExpr::create(WasmSym, MCSymbolRefExpr::VK_WASM_TYPEINDEX, Ctx);
+      MCSymbolRefExpr::create(WasmSym, WebAssembly::S_TYPEINDEX, Ctx);
   return MCOperand::createExpr(Expr);
 }