[BOLT] Use trunk llvm-tblgen in msvc builder

[Amir]

Summary

Capitalize on https://reviews.llvm.org/D126313 to build native llvm-tblgen
during the cross-compilation using MSVC. This would prevent build breakages when
changes are made to TableGen - when host llvm-tblgen becomes out of sync with
the trunk version.

[gkistanova]

LGTM

buildbot/osuosl/master/config/builders.py

# Builders for ML-driven compiler optimizations.
     'collapseRequests': True,
     'workernames' : ["bolt-worker"],
     'builddir': "bolt-x86_64-wine-msvc",
     'factory' : UnifiedTreeBuilder.getCmakeWithNinjaBuildFactory(
                     targets = ['bolt'],
                     checks = [],
                     depends_on_projects=['llvm','bolt'],
                     extra_configure_args=[
-                        "-DBUILD_PROGRAMS=ON",
+                        "-DCMAKE_C_COMPILER=cl",
+                        "-DCMAKE_CXX_COMPILER=cl",
                         "-DCMAKE_SYSTEM_NAME=Windows",
-                        "-DCMAKE_CROSSCOMPILING=ON",
                         "-DLLVM_APPEND_VC_REV=OFF",
                         "-DLLVM_CCACHE_BUILD=ON",
                         "-DLLVM_ENABLE_PROJECTS=bolt",
                         "-DLLVM_TARGETS_TO_BUILD=X86;AArch64",
-                        "-DLLVM_TABLEGEN=/usr/bin/llvm-tblgen",
+                        "-DLLVM_OPTIMIZED_TABLEGEN=ON",
                     ],
                     env={
                         'PATH':'/home/worker/msvc-wine/cmake/bin:/home/worker/msvc-wine/msvc/bin/x64:/usr/bin:/bin',
-                        'CC': 'cl', 'CXX': 'cl',
                     })},
 
     # AMD ROCm support.
     {'name' : 'mlir-rocm-mi200',
      'tags'  : ["mlir"],
      'collapseRequests' : False,
      'workernames' : ['mi200-buildbot'],
      'builddir': 'mlir-rocm-mi200',