Revert "[lld-macho] Warn on method name collisions from category defi…

…nitions"

This reverts commit ef12275.

Apparently it is causing some crashes:
https://reviews.llvm.org/D142916#4178869

lld/MachO/Driver.cpp

@@ -1920,8 +1920,6 @@ bool macho::link(ArrayRef<const char *> argsArr, llvm::raw_ostream &stdoutOS,
     if (config->deadStrip)
       markLive();
 
-    objc::checkCategories();
-
     // ICF assumes that all literals have been folded already, so we must run
     // foldIdenticalLiterals before foldIdenticalSections.
     foldIdenticalLiterals();

lld/MachO/InputFiles.cpp

@@ -1272,10 +1272,13 @@ static CIE parseCIE(const InputSection *isec, const EhReader &reader,
     }
   }
   if (personalityAddrOff != 0) {
-    const auto *personalityReloc = isec->getRelocAt(personalityAddrOff);
-    if (!personalityReloc)
+    auto personalityRelocIt =
+        llvm::find_if(isec->relocs, [=](const macho::Reloc &r) {
+          return r.offset == personalityAddrOff;
+        });
+    if (personalityRelocIt == isec->relocs.end())
       reader.failOn(off, "Failed to locate relocation for personality symbol");
-    cie.personalitySymbol = personalityReloc->referent.get<macho::Symbol *>();
+    cie.personalitySymbol = personalityRelocIt->referent.get<macho::Symbol *>();
   }
   return cie;
 }

lld/MachO/InputSection.cpp

@@ -135,14 +135,6 @@ std::string InputSection::getSourceLocation(uint64_t off) const {
   return {};
 }
 
-const Reloc *InputSection::getRelocAt(uint32_t off) const {
-  auto it = llvm::find_if(
-      relocs, [=](const macho::Reloc &r) { return r.offset == off; });
-  if (it == relocs.end())
-    return nullptr;
-  return &*it;
-}
-
 void ConcatInputSection::foldIdentical(ConcatInputSection *copy) {
   align = std::max(align, copy->align);
   copy->live = false;
@@ -267,15 +259,6 @@ const StringPiece &CStringInputSection::getStringPiece(uint64_t off) const {
   return const_cast<CStringInputSection *>(this)->getStringPiece(off);
 }
 
-size_t CStringInputSection::getStringPieceIndex(uint64_t off) const {
-  if (off >= data.size())
-    fatal(toString(this) + ": offset is outside the section");
-
-  auto it =
-      partition_point(pieces, [=](StringPiece p) { return p.inSecOff <= off; });
-  return std::distance(pieces.begin(), it) - 1;
-}
-
 uint64_t CStringInputSection::getOffset(uint64_t off) const {
   const StringPiece &piece = getStringPiece(off);
   uint64_t addend = off - piece.inSecOff;

lld/MachO/InputSection.h

@@ -55,8 +55,6 @@ class InputSection {
   // Return the source line corresponding to an address, or the empty string.
   // Format: Source.cpp:123 (/path/to/Source.cpp:123)
   std::string getSourceLocation(uint64_t off) const;
-  // Return the relocation at \p off, if it exists. This does a linear search.
-  const Reloc *getRelocAt(uint32_t off) const;
   // Whether the data at \p off in this InputSection is live.
   virtual bool isLive(uint64_t off) const = 0;
   virtual void markLive(uint64_t off) = 0;
@@ -220,10 +218,6 @@ class CStringInputSection final : public InputSection {
     return toStringRef(data.slice(begin, end - begin));
   }
 
-  StringRef getStringRefAtOffset(uint64_t off) const {
-    return getStringRef(getStringPieceIndex(off));
-  }
-
   // Returns i'th piece as a CachedHashStringRef. This function is very hot when
   // string merging is enabled, so we want to inline.
   LLVM_ATTRIBUTE_ALWAYS_INLINE
@@ -238,9 +232,6 @@ class CStringInputSection final : public InputSection {
 
   bool deduplicateLiterals = false;
   std::vector<StringPiece> pieces;
-
-private:
-  size_t getStringPieceIndex(uint64_t off) const;
 };
 
 class WordLiteralInputSection final : public InputSection {