Infinite loop in SemaHLSL when compiling weird array

Description

DXC loops indefinitely when building a simple HLSL shader with a weird array initializer.
Affects both DXIL and SPIR-V.

Seems like the loop is in SemaHLSL.cpp:

Process 3039522 stopped
* thread #1, name = 'dxc', stop reason = step over
    frame #0: 0x00007ffff57eb0c2 libdxcompiler.so`FlattenedTypeIterator::FlattenedTypeIterator(this=0x00007fffffff2fe0, loc=(ID = 46), type=QualType @ 0x00007fffffff2df0, source=0x0000555555a02310) at SemaHLSL.cpp:11857:7
   11854	      m_incompleteCount(0), m_typeDepth(0), m_loc(loc) {
   11855	  if (pushTrackerForType(type, nullptr)) {
   11856	    while (!m_typeTrackers.empty() && !considerLeaf())
-> 11857	      consumeLeaf();
   11858	  }
   11859	}
   11860

Steps to Reproduce

[numthreads(1, 1, 1)]
void main() {
  float array[1][0] = { {} };
}

./build/bin/dxc -T cs_6_0 -E main loop.hlsl

Environment

• DXC version: HEAD (130877392c263888ef06bab768856d3dab1f1c9a)
• Host Operating System : linux

Reproduce the issue with the provided HLSL shader and dxc command, then inspect FlattenedTypeIterator in SemaHLSL.cpp around line 11857. Trace why the constructor's loop does not make progress for the zero-length array initializer. Done means compilation terminates for the reproducer, with behavior checked for both DXIL and SPIR-V.