Tweaks from Andreas.

From-SVN: r17487

gcc/install.texi

@@ -182,7 +182,7 @@ make a difference.
 @cindex Haifa scheduler
 @cindex scheduler, experimental
 @item --enable-haifa
-@item --disable-haifa
+@itemx --disable-haifa
 Use @samp{--enable-haifa} to enable use of an experimental instruction
 scheduler (from IBM Haifa).  This may or may not produce better code.
 Some targets on which it is known to be a win enable it by default; use

gcc/invoke.texi

@@ -5540,8 +5540,8 @@ functions defined in the code, and makes them publicly visible.
 @cindex aliasing of parameters
 @cindex parameters, aliased
 @item -fargument-alias
-@item -fargument-noalias
-@item -fargument-noalias-global
+@itemx -fargument-noalias
+@itemx -fargument-noalias-global
 Specify the possible relationships among parameters and between
 parameters and global data.
 

gcc/tm.texi

@@ -2038,7 +2038,7 @@ between these kinds.
 @findex EXTRA_CONSTRAINT
 @item EXTRA_CONSTRAINT (@var{value}, @var{c})
 A C expression that defines the optional machine-dependent constraint
-letters (@item @samp{Q}, @samp{R}, @samp{S}, @samp{T}, @samp{U}) that can
+letters (@samp{Q}, @samp{R}, @samp{S}, @samp{T}, @samp{U}) that can
 be used to segregate specific types of operands, usually memory
 references, for the target machine.  Normally this macro will not be
 defined.  If it is required for a particular target machine, it should