[gardening] Format two doxygen comments according to LLVM style guide. NFC.

Author: gottesmm

include/swift/SILOptimizer/Analysis/AliasAnalysis.h

@@ -22,24 +22,26 @@
 using swift::RetainObserveKind;
 
 namespace {
-  /// A cache for AliasAnalysis.
-  /// This struct represents the argument list to the method 'alias'.
-  /// The two SILValue pointers are mapped to size_t indices because we need
-  /// an efficient way to invalidate them (the mechanism is described below).
-  /// The Type arguments are translated to void* because their
-  /// underlying storage is opaque pointers that never goes away.
+/// A key used for the AliasAnalysis cache.
+///
+/// This struct represents the argument list to the method 'alias'.  The two
+/// SILValue pointers are mapped to size_t indices because we need an
+/// efficient way to invalidate them (the mechanism is described below). The
+/// Type arguments are translated to void* because their underlying storage is
+/// opaque pointers that never goes away.
   struct AliasKeyTy {
     // The SILValue pair:
     size_t V1, V2;
     // The TBAAType pair:
     void *T1, *T2;
   };
 
-  /// A cache for MemoryBehavior Analysis.
-  /// The two SILValue pointers are mapped to size_t indices because we need
-  /// an efficient way to invalidate them (the mechanism is described below).
-  /// The RetainObserveKind represents the inspection mode for the memory
-  /// behavior analysis.
+  /// A key used for for the MemoryBehavior Analysis cache.
+  ///
+  /// The two SILValue pointers are mapped to size_t indices because we need an
+  /// efficient way to invalidate them (the mechanism is described below).  The
+  /// RetainObserveKind represents the inspection mode for the memory behavior
+  /// analysis.
   struct MemBehaviorKeyTy {
     // The SILValue pair:
     size_t V1, V2;
@@ -100,11 +102,13 @@ class AliasAnalysis : public SILAnalysis {
   llvm::DenseMap<TBAACacheKey, bool> TypesMayAliasCache;
 
   /// AliasAnalysis value cache.
+  ///
   /// The alias() method uses this map to cache queries.
   llvm::DenseMap<AliasKeyTy, AliasResult> AliasCache;
 
   using MemoryBehavior = SILInstruction::MemoryBehavior;
   /// MemoryBehavior value cache.
+  ///
   /// The computeMemoryBehavior() method uses this map to cache queries.
   llvm::DenseMap<MemBehaviorKeyTy, MemoryBehavior> MemoryBehaviorCache;