[X86] Restrict many of the InstAliases to either to only att or intel syntax. NFCI

Many of these aliases exist to give one syntax or the other a slightly different mnemonic and the other variant gets a duplicate of its normal mnemonic

This patch restricts a lot of these to only one variant so we don't get the duplication.

This removes a lot of duplicate entries from the matcher table. It also reduces the number of warnings printed when you enable the ambiguous match warning in tablegen.

llvm-svn: 331117