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/ARM/ARMConstantIslandPass.cpp b/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
index cdbd360..7411caf 100644
--- a/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
+++ b/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
@@ -480,7 +480,7 @@
   return MadeChange;
 }
 
-/// \brief Perform the initial placement of the regular constant pool entries.
+/// Perform the initial placement of the regular constant pool entries.
 /// To start with, we put them all at the end of the function.
 void
 ARMConstantIslands::doInitialConstPlacement(std::vector<MachineInstr*> &CPEMIs) {
@@ -540,7 +540,7 @@
   DEBUG(BB->dump());
 }
 
-/// \brief Do initial placement of the jump tables. Because Thumb2's TBB and TBH
+/// Do initial placement of the jump tables. Because Thumb2's TBB and TBH
 /// instructions can be made more efficient if the jump table immediately
 /// follows the instruction, it's best to place them immediately next to their
 /// jumps to begin with. In almost all cases they'll never be moved from that
@@ -1929,7 +1929,7 @@
   return true;
 }
 
-/// \brief While trying to form a TBB/TBH instruction, we may (if the table
+/// While trying to form a TBB/TBH instruction, we may (if the table
 /// doesn't immediately follow the BR_JT) need access to the start of the
 /// jump-table. We know one instruction that produces such a register; this
 /// function works out whether that definition can be preserved to the BR_JT,
@@ -2017,7 +2017,7 @@
   return true;
 }
 
-/// \brief Returns whether CPEMI is the first instruction in the block
+/// Returns whether CPEMI is the first instruction in the block
 /// immediately following JTMI (assumed to be a TBB or TBH terminator). If so,
 /// we can switch the first register to PC and usually remove the address
 /// calculation that preceded it.