Remove \brief commands from doxygen comments.

This is similar to the LLVM change https://reviews.llvm.org/D46290.

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

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
diff --git a/clang/include/clang-c/CXErrorCode.h b/clang/include/clang-c/CXErrorCode.h
index aff73b7..caee48d 100644
--- a/clang/include/clang-c/CXErrorCode.h
+++ b/clang/include/clang-c/CXErrorCode.h
@@ -21,19 +21,19 @@
 #endif
 
 /**
- * \brief Error codes returned by libclang routines.
+ * Error codes returned by libclang routines.
  *
  * Zero (\c CXError_Success) is the only error code indicating success.  Other
  * error codes, including not yet assigned non-zero values, indicate errors.
  */
 enum CXErrorCode {
   /**
-   * \brief No error.
+   * No error.
    */
   CXError_Success = 0,
 
   /**
-   * \brief A generic error code, no further details are available.
+   * A generic error code, no further details are available.
    *
    * Errors of this kind can get their own specific error codes in future
    * libclang versions.
@@ -41,18 +41,18 @@
   CXError_Failure = 1,
 
   /**
-   * \brief libclang crashed while performing the requested operation.
+   * libclang crashed while performing the requested operation.
    */
   CXError_Crashed = 2,
 
   /**
-   * \brief The function detected that the arguments violate the function
+   * The function detected that the arguments violate the function
    * contract.
    */
   CXError_InvalidArguments = 3,
 
   /**
-   * \brief An AST deserialization error has occurred.
+   * An AST deserialization error has occurred.
    */
   CXError_ASTReadError = 4
 };