Use -print-prog-name instead of -print-file-name in gcc spkg-configure.m4 #28317
Description
Here's what I get
~/sage$ echo $CC
/projects/66d93023-00f0-4c12-8a25-5d6d4e486740/sage-build/bin/x86_64-conda_cos6-linux-gnu-cc
~/sage$ $CC -print-prog-name=ld
/projects/66d93023-00f0-4c12-8a25-5d6d4e486740/sage-build/bin/../lib/gcc/x86_64-conda_cos6-linux-gnu/7.3.0/../../../../x86_64-conda_cos6-linux-gnu/bin/ld
~/sage$ $CC -print-file-name=ld
ld
~/sage$ echo $LD
/projects/66d93023-00f0-4c12-8a25-5d6d4e486740/sage-build/bin/x86_64-conda_cos6-linux-gnu-ld
Therefore -print-file-name is clearly not what we need.
-print-prog-name gives a path with ..s in it.
We need to check that the two files are equivalent using -ef which checks that the files are the same.
Component: build: configure
Author: Isuru Fernando
Branch/Commit: dec073b
Reviewer: Dima Pasechnik
Issue created by migration from https://trac.sagemath.org/ticket/28317