docs: fix Function Attributes table nesting.

[Ralf Wildenhues]

The tables are nested here, wrongly, leading to very far indented text.
One cannot use heading markup inside a table, so I'm removing the
mock-markup.  I don't think it suffers much from it.

Tested make info pdf html, OK for trunk?

Thanks,
Ralf

docs: fix Function Attributes table nesting.

gcc/ChangeLog:
2011-02-27  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>

	* doc/extend.texi (Function Attributes): Avoid deeply (and
	wrongly) nested tables.

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 6751360..eaad089 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -3291,8 +3291,6 @@ int core2_func (void) __attribute__ ((__target__ ("arch=core2")));
 int sse3_func (void) __attribute__ ((__target__ ("sse3")));
 @end smallexample
 
-@table @samp
-@item i386 target attributes
 On the 386, the following options are allowed:
 
 @table @samp
@@ -3435,8 +3433,8 @@ Specify which floating point unit to use.  The
 @code{target("fpmath=sse,387")} option must be specified as
 @code{target("fpmath=sse+387")} because the comma would separate
 different options.
+@end table
 
-@item PowerPC target attributes
 On the PowerPC, the following options are allowed:
 
 @table @samp
@@ -3608,8 +3606,6 @@ you do specify the @code{target("cpu=@var{CPU}")} attribute,
 compilation will tune for the @var{CPU} architecture, and not the
 default tuning specified on the command line.
 @end table
-@end table
-@end table
 
 On the 386/x86_64 and PowerPC backends, you can use either multiple
 strings to specify multiple options, or you can separate the option