support reproduce with namespec

Add support for reproduce with namespec support

cat > 1.c << \!
int foo() { return 0; }
!

cat > 2.c << \!
int bar() { return 0; }
!

rm -f lib2.* && clang -c -target x86_64 -c 2.c
ld.eld -shared 2.o -o lib2.so
clang -c -target x86_64 -c 1.c
ld.eld -Bdynamic 1.o -L. -l:lib2.so -o a --reproduce a.tar

namespec notes

If namespec is of the form :filename, ld will search the library path for a file called filename, otherwise it will search the library path for a file called libnamespec.a

Running the reproduce produces this message :

 (rm -rf reproduce.a;tar xf a.tar) && cd reproduce.a && bash -x response.txt
+ ld.eld -Bdynamic Object/1.o.6201977920901693556 lib2.so -o a --mapping-file=mapping.ini
Fatal: cannot read file 'lib2.so'
Fatal: Linking had errors.