commit a884b93c21e02cec786a9a83e773288f3a354413
author Stanley Winata <68087699+raikonenfnu@users.noreply.github.com> Fri Aug 16 17:48:22 2024 -0700
committer GitHub <noreply@github.com> Fri Aug 16 17:48:22 2024 -0700
tree 3525de82966d805daf726e0770f9300f6bce4a97
parent 0e152d2760abedf29d1f718dbc9754fd47ec77ab

Bump LLVM to llvm/llvm-project@ddda37a (#18258)

Bump LLVM upstream while reverting
https://github.com/llvm/llvm-project/pull/104630 due to issues which
will be detailed below.

Potential fixes:
https://github.com/llvm/llvm-project/pull/104630 for issue no.1
https://github.com/llvm/llvm-project/pull/104648 for issue no.2

https://github.com/llvm/llvm-project/pull/104630 breaks 2 things:

1.vm.call + emitc to c code generation.
```mlir
error: null operand found
    vm.check.eq %ref_dno, %res, "_v_r()=NULL" : !vm.ref<?>
%11 = "emitc.call_opaque"(%8, <<NULL VALUE>>) <{callee = "vm_cmp_eq_ref"}> : (!emitc.ptr<!emitc.opaque<"iree_vm_ref_t">>, <<NULL TYPE>>) -> i32
```
2. memref_util_test failure due to populateMemrefUtilPatterns not
properly legalizing `builtin.unrealized_conversion_cast`, even though we
expected `builtin.unrealized_conversion_cast`.
```mlir
memref_util_test.mlir:1:79: error: failed to legalize unresolved materialization from ('i32') to 'i16' that remained live after conversion
util.func @load_store_i16(%buffer: memref<?xi16>, %idx0: index, %idx1: index, %value: i16) -> i16 {
                                                                              ^
memref_util_test.mlir:1:79: note: see current operation: %0 = "builtin.unrealized_conversion_cast"(%arg3) : (i32) -> i16
memref_util_test.mlir:7:3: note: see existing live user here: "util.buffer.store"(%0, %arg0, %4, %6, %5) : (i16, !util.buffer, index, index, index) -> ()
  memref.store %value, %buffer[%idx0] : memref<?xi16>
  ^
memref_util_test.mlir:0:0: error: conversion to util failed
memref_util_test.mlir:0:0: note: see current operation:
"builtin.module"() ({
  "util.func"() <{function_type = (memref<?xi16>, index, index, i16) -> i16, sym_name = "load_store_i16", tied_operands = [-1 : index]}> ({
  ^bb0(%arg0: memref<?xi16>, %arg1: index, %arg2: index, %arg3: i16):
    "memref.store"(%arg3, %arg0, %arg1) : (i16, memref<?xi16>, index) -> ()
    %0 = "memref.load"(%arg0, %arg2) : (memref<?xi16>, index) -> i16
    "util.return"(%0) : (i16) -> ()
  }) : () -> ()
}) : () -> ()
```

---------

Signed-off-by: Stanley Winata <stanley@nod-labs.com>