[llvm] [LoongArch] Add relax feature and keep relocations (PR #72191)

[Fangrui Song via llvm-commits]

================
@@ -20,19 +20,27 @@ using namespace llvm;
 namespace {
 class LoongArchELFObjectWriter : public MCELFObjectTargetWriter {
 public:
-  LoongArchELFObjectWriter(uint8_t OSABI, bool Is64Bit);
+  LoongArchELFObjectWriter(uint8_t OSABI, bool Is64Bit, bool EnableRelax);
 
   ~LoongArchELFObjectWriter() override;
 
+  bool needsRelocateWithSymbol(const MCValue &Val, const MCSymbol &Sym,
+                               unsigned Type) const override {
+    return EnableRelax;
+  }
+
 protected:
   unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
                         const MCFixup &Fixup, bool IsPCRel) const override;
+  bool EnableRelax;
 };
 } // end namespace
 
-LoongArchELFObjectWriter::LoongArchELFObjectWriter(uint8_t OSABI, bool Is64Bit)
+LoongArchELFObjectWriter::LoongArchELFObjectWriter(uint8_t OSABI, bool Is64Bit,
+                                                   bool EnableRelax)
     : MCELFObjectTargetWriter(Is64Bit, OSABI, ELF::EM_LOONGARCH,
-                              /*HasRelocationAddend*/ true) {}
+                              /*HasRelocationAddend*/ true),
----------------
MaskRay wrote:

The canonical comment style is `/*HasRelocationAddend=*/true`

https://github.com/llvm/llvm-project/pull/72191