Error out when building a shared library / dynamic executable if incompatible relocations are present in input files

[parth-07]

We should error out when building a shared library / dynamic executable if incompatible relocations are present in the input files for the current linking model.

Reproducer:

#!/usr/bin/env bash

cat >1.c <<\EOF
#include <stdio.h>

int u ;

int main() { 
  u = 11;
  printf("u: %d\n", u);
  return 0;
}
EOF

cat >u.c <<\EOF
int u = 11;

int foo() { return u; }
EOF

musl-clang -o u.o u.c -c -ffunction-sections -fno-pic
LD=eld musl-clang -o libu.eld.so u.o -shared

The link works fine but it should fail with the error: invalid relocation 'R_X86_64_32S' against symbol u.