LLVM / Clang compilation hangs on Windows

No matter which LLVM version is used (19 or the latest 23) and which Visual Studio Community version (tested on 2022 and 2026, both up to date), trying to compile the solution hangs some steps after the compilation of omp_gen started:

86>------ Inizio compilazione: Progetto: omp_gen, Configurazione: Release x64 ------
79> ClangTypeNodesEmitter.cpp
86> 2>Building OMP.inc...
86> 1>Building OMP.h.inc...
83> 4>Building IntrinsicsHexagon.h...
85> 1>Building GenVT.inc...
79> HLSLEmitter.cpp
79> MveEmitter.cpp
79> NeonEmitter.cpp
82> 4>Building RISCVTargetParserDef.inc...
79> RISCVVEmitter.cpp
79> SveEmitter.cpp
79> TableGen.cpp
83> 2>Building IntrinsicsAArch64.h...
83> 6>Building IntrinsicsRISCV.h...
83> 5>Building IntrinsicsNVPTX.h...

Everytime it hangs just when started building the first Intrinsics*.h files (the last one isn't the same file: it changes), on Windows 11 Pro (lastest build).
It's not possible to stop the compilation or exit VS: it always says that there's a pending compilation which should be completed: it needs to be brutally terminate via Task Manager.
Unfortunaly, many instances of some processes remain running: cmd.exe, conhost.exe, llvm-min-tblgen.exe. Even trying to force kill them, many are still displayed on the Task Manager, and they can't be killed also when using admin privileges: the only way is a reboot of the machine.

Cmake build folder generations performed with the following parameters:
cmake -S llvm\llvm -Thost=x64 -B build-llvm-vs -DLLVM_PARALLEL_COMPILE_JOBS=4 -DLLVM_PARALLEL_LINK_JOBS=2 -DLLVM_ENABLE_PROJECTS=clang -DLLVM_TARGETS_TO_BUILD=AArch64;ARM;X86;RISCV -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="M68k"
cmake -S llvm\llvm -Thost=x64 -B build-llvm-vs -DLLVM_ENABLE_PROJECTS=clang;lld -DLLVM_TARGETS_TO_BUILD=AArch64;ARM;X86;RISCV -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="M68k"
cmake -S llvm\llvm -Thost=x64 -B build-llvm-vs -DLLVM_ENABLE_PROJECTS=clang -DLLVM_TARGETS_TO_BUILD=AArch64;ARM;X86;RISCV -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="M68k"
without any success (always the same hung).

VS 2026 version: 18.7.2

PC info:
Processore Intel(R) Core(TM) i5-8500 CPU @ 3.00GHz (3.00 GHz)
RAM installata 32,0 GB (31,7 GB utilizzabile)
Scheda grafica NVIDIA GeForce GTX 1050 Ti (4 GB)
Intel(R) UHD Graphics 630 (128 MB)

Windows Info:
Edizione Windows 11 Pro
Versione 25H2
Build sistema operativo 26200.8737
Feature Pack Pacchetto di esperienze per funzionalità Windows 1000.26100.334.0

Reproduce the Windows 11 build using the listed CMake commands and observe the hang while generating Intrinsics*.h after omp_gen starts. Inspect the omp_gen and llvm-min-tblgen processes and the affected generation step; done means the underlying hang is identified and a validated fix or focused diagnostic is provided.

Written by the indexing model from the issue text.