Add llvm-ml64 to LLVM_TOOLCHAIN_TOOLS (#158582)

So that it gets included in LLVM_INSTALL_TOOLCHAIN_ONLY builds, such as
when building the Windows installer.

Fixes #149664

Author: zmodem

llvm/cmake/modules/AddLLVM.cmake

@@ -1442,6 +1442,7 @@ if(NOT LLVM_TOOLCHAIN_TOOLS)
     llvm-lib
     llvm-mca
     llvm-ml
+    llvm-ml64
     llvm-nm
     llvm-objcopy
     llvm-objdump