scripts: refine static linking check to better guide the user

The current mechanism to check if static linking is possible, and the mesage
displayed on failure, can be puzzling to the unsuspecting user.

Also, the current implementation is not using the existing infrastructure,
and is thus difficult to enhance with new tests.

So, switch to using the standard CT_DoExecLog infra, and use four tests to
check for the host compiler:
- check we can run it
- check it can build a trivial program
- check it can statically link that program
- check if it statically link with libstdc++

That should cover most of the problems. Hopefully.

(At the same time, fix a typo in a comment)

Signed-off-by: Daniel Price <daniel.price@gmail.com>
[yann.morin.1998@free.fr: split original patch for self-contained changes]
[yann.morin.1998@free.fr: use steps to better see gcc's output]
[yann.morin.1998@free.fr: commit log]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <163f86b5216fc08c672a.1353459722@nipigon.dssd.com>
Patchwork-Id: 200536

 # Binary utilities menu

 menu "Binary utilities"

 choice

     bool

     prompt "Binary format:"

 config ARCH_BINFMT_ELF

     bool

     prompt "ELF"

     depends on ARCH_USE_MMU || BARE_METAL

     help

       This will make your system build ELF executables,

       suitable for architectures with an MMU.

 config ARCH_BINFMT_FLAT

     bool

     prompt "Flat"

     depends on ! ARCH_USE_MMU

     help

       This will build flat binaries, suitable for

       MMU-less architectures.

 config ARCH_BINFMT_FDPIC

     bool

     prompt "FD_PIC ELF"

     depends on ! ARCH_USE_MMU

     help

       This will build FD_PIC ELF binaries, suitable for

       MMU-less architectures that still require to use

       shared libraries (FIXME).

 endchoice

 config BINUTILS

     string

 source "config.gen/binutils.in"

 source "config.gen/binutils.in.2"

 endmenu