[ELF] Add comment for preemptible and fix typo. NFC

[MaskRay]

repeated word typo

[ruiu]

ELF/Symbols.h

157

Is this correct? I thought IsPreemptible=true means the symbol is preemptible at load time. I don't think "a symbol preemptible at link time" is a well defined concept.

[MaskRay]

ELF/Symbols.h

157

Fixed in the latest commit. I did not know that I can commit when this revision was in the "Need review" status. I saw a LGTM on my phone.

ELF/Symbols.h

public:
   bool isDefined() const { return SymbolKind == DefinedKind; }
   bool isShared() const { return SymbolKind == SharedKind; }
   bool isLocal() const { return Binding == llvm::ELF::STB_LOCAL; }
 
   bool isLazy() const {
     return SymbolKind == LazyArchiveKind || SymbolKind == LazyObjectKind;
   }
 
-  // True is this is an undefined weak symbol. This only works once
+  // True if this is an undefined weak symbol. This only works once
   // all input files have been added.
   bool isUndefWeak() const {
-    // See comment on Lazy the details.
+    // See comment on Lazy for details.
     return isWeak() && (isUndefined() || isLazy());
   }
 
   StringRef getName() const { return Name; }
   void parseSymbolVersion();
 
   bool isInGot() const { return GotIndex != -1U; }
   bool isInPlt() const { return PltIndex != -1U; }
public:
   unsigned Is32BitMipsGot : 1;
 
   // True if this symbol is in the Iplt sub-section of the Plt.
   unsigned IsInIplt : 1;
 
   // True if this symbol is in the Igot sub-section of the .got.plt or .got.
   unsigned IsInIgot : 1;
 
+  // True if this symbol is preemptible at link or load time.
   unsigned IsPreemptible : 1;
 
   // True if an undefined or shared symbol is used from a live section.
   unsigned Used : 1;
 
   // The following fields have the same meaning as the ELF symbol attributes.
   uint8_t Type;    // symbol type
   uint8_t StOther; // st_other field value