Remove \brief commands from doxygen comments.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.h b/llvm/lib/Target/PowerPC/PPCISelLowering.h
index 76f8d72..b4373c1 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.h
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.h
@@ -765,7 +765,7 @@
 
     bool isFPExtFree(EVT DestVT, EVT SrcVT) const override;
 
-    /// \brief Returns true if it is beneficial to convert a load of a constant
+    /// Returns true if it is beneficial to convert a load of a constant
     /// to just the constant itself.
     bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
                                            Type *Ty) const override;
@@ -822,7 +822,7 @@
     FastISel *createFastISel(FunctionLoweringInfo &FuncInfo,
                              const TargetLibraryInfo *LibInfo) const override;
 
-    /// \brief Returns true if an argument of type Ty needs to be passed in a
+    /// Returns true if an argument of type Ty needs to be passed in a
     /// contiguous block of registers in calling convention CallConv.
     bool functionArgumentNeedsConsecutiveRegisters(
       Type *Ty, CallingConv::ID CallConv, bool isVarArg) const override {