[X86][AMX] set Stride to Tile's Col when doing combine amxcast and store into tilestore

[X86][AMX] set Stride to Tile's Col when doing combine amxcast and store into tilestore

%tile = call x86_amx @llvm.x86.tileloadd64.internal(i16 8, i16 32, i8* %src_ptr, i64 64)
%vec = call <256 x i8> @llvm.x86.cast.tile.to.vector.v256i8(x86_amx...%tile)
store <256 x i8> %vec, <256 x i8>* %dst_ptr, align 256
=>
%tile = call x86_amx @llvm.x86.tileloadd64.internal(i16 8, i16 32, i8* %src_ptr, i64 64)
%stride = sext i16 32 to i64
call void @llvm.x86.tilestored64.internal(i16 8, i16 32, i8* %dst_ptr, i64 32, x86_amx %tile)

Reviewed By: LuoYuanke

Differential Revision: https://reviews.llvm.org/D153002