[ELF] Change std::max<uint64_t> to uint32_t for section alignment

[MaskRay]

Summary

We use uint32_t SectionBase::Alignment and `uint32_t
PhdrEntry::p_align` despite alignments being 64 bits in ELF64.
Fix the std::max template arguments accordingly.

The currently 160-byte InputSection will become 168 bytes if we make SectionBase::Alignment uint64_t.

[ruiu]

LGTM

ELF/InputSection.cpp

if (SectionKind == SectionBase::Merge && RawData.size() > UINT32_MAX)
     error(toString(this) + ": section too large");
 
   NumRelocations = 0;
   AreRelocsRela = false;
   Debug = Name.startswith(".debug") || Name.startswith(".zdebug");
 
   // The ELF spec states that a value of 0 means the section has
   // no alignment constraits.
-  uint32_t V = std::max<uint64_t>(Alignment, 1);
+  uint32_t V = std::max<uint32_t>(Alignment, 1);
   if (!isPowerOf2_64(V))
     fatal(toString(this) + ": sh_addralign is not a power of 2");
   this->Alignment = V;
 
   // In ELF, each section can be compressed by zlib, and if compressed,
   // section name may be mangled by appending "z" (e.g. ".zdebug_info").
   // If that's the case, demangle section name so that we can handle a
   // section as if it weren't compressed.
if (Config->Is64) {
 
     auto *Hdr = reinterpret_cast<const Chdr64 *>(RawData.data());
     if (Hdr->ch_type != ELFCOMPRESS_ZLIB) {
       error(toString(this) + ": unsupported compression type");
       return;
     }
 
     UncompressedSize = Hdr->ch_size;
-    Alignment = std::max<uint64_t>(Hdr->ch_addralign, 1);
+    Alignment = std::max<uint32_t>(Hdr->ch_addralign, 1);
     RawData = RawData.slice(sizeof(*Hdr));
     return;
   }
 
   // New-style 32-bit header
   if (RawData.size() < sizeof(Chdr32)) {
     error(toString(this) + ": corrupted compressed section");
     return;
   }
 
   auto *Hdr = reinterpret_cast<const Chdr32 *>(RawData.data());
   if (Hdr->ch_type != ELFCOMPRESS_ZLIB) {
     error(toString(this) + ": unsupported compression type");
     return;
   }
 
   UncompressedSize = Hdr->ch_size;
-  Alignment = std::max<uint64_t>(Hdr->ch_addralign, 1);
+  Alignment = std::max<uint32_t>(Hdr->ch_addralign, 1);
   RawData = RawData.slice(sizeof(*Hdr));
 }
 
 InputSection *InputSectionBase::getLinkOrderDep() const {
   assert(Link);
   assert(Flags & SHF_LINK_ORDER);
   return cast<InputSection>(File->getSections()[Link]);
 }