[Bug testsuite/90368] New: gdc testsuite uses "ln -s . gdc.test", which doesn't work on msys2

[rainer@emrich-ebersheim.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90368

            Bug ID: 90368
           Summary: gdc testsuite uses "ln -s . gdc.test", which doesn't
                    work on msys2
           Product: gcc
           Version: 9.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: testsuite
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rainer@emrich-ebersheim.de
  Target Milestone: ---

The gdc testsuite uses "ln -s . gdc.test" to link gec.test in the testsuite/gdc
directory. This doesn't work on msys2 and leads to an error:

ERROR: tcl error sourcing
/opt/devel/gnu/src/gcc-mingw-w64/gcc-9.1.0/gcc/testsuite/gdc.test/gdc-test.exp.
ERROR: couldn't open "gdc.test/compilable/99bottles.d": no such file or
directory
    while executing
"open $file r"
    (procedure "grep" line 19)
    invoked from within
"grep $prog "{\[ \t\]\+dg-\[-a-z\]\+\[ \t\]\+.*\[ \t\]\+}" line"
    (procedure "dg-get-options" line 4)
    invoked from within
"dg-get-options $prog"
    (procedure "saved-dg-test" line 75)
    invoked from within
"saved-dg-test gdc.test/compilable/99bottles.d { }
-I/opt/devel/gnu/src/gcc-mingw-w64/gcc-9.1.0/gcc/testsuite/gdc.test/compilable"
    ("eval" body line 1)
    invoked from within
"eval saved-dg-test $args "
    (procedure "dg-test" line 4)
    invoked from within
"dg-test $test "$flags $flags_t" ${default-extra-flags}"
    (procedure "gdc-dg-runtest" line 23)
    invoked from within
"gdc-dg-runtest $filename $flags $imports"
    (procedure "gdc-do-test" line 86)
    invoked from within
"gdc-do-test"
    (file
"/opt/devel/gnu/src/gcc-mingw-w64/gcc-9.1.0/gcc/testsuite/gdc.test/gdc-test.exp"
line 468)
    invoked from within
"source
/opt/devel/gnu/src/gcc-mingw-w64/gcc-9.1.0/gcc/testsuite/gdc.test/gdc-test.exp"
    ("uplevel" body line 1)
    invoked from within
"uplevel #0 source
/opt/devel/gnu/src/gcc-mingw-w64/gcc-9.1.0/gcc/testsuite/gdc.test/gdc-test.exp"
    invoked from within
"catch "uplevel #0 source $test_file_name""