llvm-ml with "-m64" command line flag by default for 64 bit package

[marakew]

it makes sense to enable this flag by default
for packages built for a 64-bit platform

the compiler and linker use 64-bit generation by default
but the assembler cannot be used without this additional flag
this causes inconvenience when using cmake
like boost context
where cmake determines that the x64_86 architecture
but when starting to build llvm-ml.exe as for 32-bit mode

or for 64-bit platforms make an ml64 build
where this flag will be enabled by default

[marakew]

#131854
I'm surprised
it turns out this has already been implemented
but for some reason not in the final build of the llvm package for Windows

[marakew]

@zmodem
why don't you include this file in the build for Windows?
i mean llvm-ml64.exe

[zmodem]

It's because llvm-ml64 isn't part of LLVM_TOOLCHAIN_TOOLS:

llvm-project/llvm/cmake/modules/AddLLVM.cmake

Lines 1435 to 1470 in e4124c0

	set (LLVM_TOOLCHAIN_TOOLS
	llvm-ar
	llvm-cov
	llvm-cxxfilt
	llvm-dlltool
	llvm-dwp
	llvm-ranlib
	llvm-lib
	llvm-mca
	llvm-ml
	llvm-nm
	llvm-objcopy
	llvm-objdump
	llvm-pdbutil
	llvm-rc
	llvm-readobj
	llvm-size
	llvm-strings
	llvm-strip
	llvm-profdata
	llvm-profgen
	llvm-symbolizer
	# symlink version of some of above tools that are enabled by
	# LLVM_INSTALL_BINUTILS_SYMLINKS.
	addr2line
	ar
	c++filt
	ranlib
	nm
	objcopy
	objdump
	readelf
	size
	strings
	strip
	)

Would you like to send a PR to fix it? Otherwise I can do it.

[marakew]

send from yourself
i think @ericastor just forget about this changes