[lldb] install lldb-tblgen by default to ease cross-compilation (one-liner) (#159812)

Right now, cross-building `lldb` means either installing a native
`lldb-tblgen` by hand (non-trivial, as CMake is painful) or first
building all of native clang because of how the CMake rules work, which
is not fun.

In keeping with the pattern established by llvm-tblgen and clang-tblgen,
install lldb-tblgen to ease cross-compilation.

Co-authored-by: Ross Burton <ross.burton@arm.com>

lldb/utils/TableGen/CMakeLists.txt

diff --git a/lldb/utils/TableGen/CMakeLists.txt b/lldb/utils/TableGen/CMakeLists.txt
index 0ac010b..ce96ddd 100644
--- a/lldb/utils/TableGen/CMakeLists.txt
+++ b/lldb/utils/TableGen/CMakeLists.txt
@@ -8,6 +8,7 @@
     set(LLVM_LINK_COMPONENTS Support)
 
     add_tablegen(lldb-tblgen LLDB
+      DESTINATION "${CMAKE_INSTALL_BINDIR}"
       LLDBOptionDefEmitter.cpp
       LLDBPropertyDefEmitter.cpp
       LLDBTableGen.cpp