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

diff -uNpr gcc-4.2.1_orig/gcc/config/rs6000/darwin-ldouble.c gcc-4.2.1/gcc/config/rs6000/darwin-ldouble.c

--- gcc-4.2.1_orig/gcc/config/rs6000/darwin-ldouble.c	2007-03-05 11:54:00.000000000 -0500

+++ gcc-4.2.1/gcc/config/rs6000/darwin-ldouble.c	2008-01-31 17:51:24.000000000 -0500

@@ -70,6 +70,8 @@ Software Foundation, 51 Franklin Street,

    but GCC currently generates poor code when a union is used to turn

    a long double into a pair of doubles.  */

+#if defined (_SOFT_FLOAT) && defined (__LONG_DOUBLE_128__)

+

 long double __gcc_qadd (double, double, double, double);

 long double __gcc_qsub (double, double, double, double);

 long double __gcc_qmul (double, double, double, double);

@@ -219,8 +221,6 @@ __gcc_qdiv (double a, double b, double c

   return z.ldval;

 }

-#if defined (_SOFT_FLOAT) && defined (__LONG_DOUBLE_128__)

-

 long double __gcc_qneg (double, double);

 int __gcc_qeq (double, double, double, double);

 int __gcc_qne (double, double, double, double);