Remove remaining memref.dealloc after InsertGpuAllocs pass

[dchigarev]

This PR fixes the following buggy behavior that caused double deallocations:

// this is how insert-gpu-allocs worked sometimes before the fix
// before insert-gpu-allocs pass
func.func @test() {
    %0 = memref.alloc() : memref<32x4096xf16>
    ...
    memref.dealloc %0: memref<32x4096xf16>
}

// after insert-gpu-allocs pass
func.func @test() {
    %0 = gpu.alloc() host_shared : memref<32x4096xf16> // memref.alloc was replaced with GPU
    ...
    memref.dealloc %0 : memref<32x4096xf16> // memref.dealloc is still there (causes crashes)
    gpu.dealloc %0 : memref<32x4096xf16> // added gpu.dealloc
}

This bug causes xegpu pipeline in graph compiler to crash on big tensors. I've noticed this problem for the first time on the new tests added by intel/graph-compiler#220. @LongshengDu have you encountered this problem already? Maybe you have another fix?

crash dump that I've seen in GC

PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: /home/jovyan/graph-compiler/build/bin/gc-cpu-runner -e main -entry-point-result=void --shared-libs=/home/jovyan/llvm/llvm-gc-master-patches-install/lib/libmlir_runner_utils.so,/home/jovyan/llvm/llvm-gc-master-patches-install/lib/libmlir_c_runner_utils.so,/home/jovyan/graph-compiler/build/lib/libGcOpenclRuntime.so
 #0 0x00005589fcc4c2a0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/jovyan/graph-compiler/build/bin/gc-cpu-runner+0x3b82a0)
 #1 0x00005589fcc493af llvm::sys::RunSignalHandlers() (/home/jovyan/graph-compiler/build/bin/gc-cpu-runner+0x3b53af)
 #2 0x00005589fcc49505 SignalHandler(int) Signals.cpp:0:0
 #3 0x00007f1def2716ac (/usr/lib/x86_64-linux-gnu/intel-opencl/libigdrcl.so+0x5436ac)
 #4 0x00007f1e29ef8520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #5 0x00007f1e29f5b3fe __libc_free ./malloc/malloc.c:3368:7
 #6 0x00007f1e2a43279d 
 #7 0x00007f1e2a432ff7 
 #8 0x00007f1e2a4338e1 
 #9 0x00005589fd205a0c compileAndExecute((anonymous namespace)::Options&, mlir::Operation*, llvm::StringRef, (anonymous namespace)::CompileAndExecuteConfig, void**, std::unique_ptr<llvm::TargetMachine, std::default_delete<llvm::TargetMachine>>) JitRunner.cpp:0:0
#10 0x00005589fd205ead compileAndExecuteVoidFunction((anonymous namespace)::Options&, mlir::Operation*, llvm::StringRef, (anonymous namespace)::CompileAndExecuteConfig, std::unique_ptr<llvm::TargetMachine, std::default_delete<llvm::TargetMachine>>) JitRunner.cpp:0:0
#11 0x00005589fd207473 mlir::JitRunnerMain(int, char**, mlir::DialectRegistry const&, mlir::JitRunnerConfig) (/home/jovyan/graph-compiler/build/bin/gc-cpu-runner+0x973473)
#12 0x00005589fcb846c0 std::vector<std::unique_ptr<mlir::DialectExtensionBase, std::default_delete<mlir::DialectExtensionBase>>, std::allocator<std::unique_ptr<mlir::DialectExtensionBase, std::default_delete<mlir::DialectExtensionBase>>>>::~vector() /usr/include/c++/11/bits/stl_vector.h:680:15
#13 0x00005589fcb846c0 mlir::DialectRegistry::~DialectRegistry() /home/jovyan/llvm/llvm-gc-master-patches-install/include/mlir/IR/DialectRegistry.h:139:7
#14 0x00005589fcb846c0 main /home/jovyan/graph-compiler/src/gc-cpu-runner/gc-cpu-runner.cpp:46:1
#15 0x00007f1e29edfd90 __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:58:16
#16 0x00007f1e29edfe40 call_init ./csu/../csu/libc-start.c:128:20
#17 0x00007f1e29edfe40 __libc_start_main ./csu/../csu/libc-start.c:379:5
#18 0x00005589fcc35195 _start (/home/jovyan/graph-compiler/build/bin/gc-cpu-runner+0x3a1195)