[Bug fortran/66175] New: ICE in gfc_free_namespace with unbalanced BLOCKs

["tkoenig at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66175

            Bug ID: 66175
           Summary: ICE in gfc_free_namespace with unbalanced BLOCKs
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tkoenig at gcc dot gnu.org
  Target Milestone: ---

ig25@linux-fd1f:~/Krempel/Block> cat ice.f90
program main
  integer :: n
  n = 3
  block
    block
      print *,n
end program main
ig25@linux-fd1f:~/Krempel/Block> gfortran ice.f90
ice.f90:7:3:

 end program main
   1
Error: Expecting END BLOCK statement at (1)
f951: Error: Unexpected end of file in Âice.f90Â
f951: internal compiler error: in gfc_free_namespace, bei fortran/symbol.c:3525
0x6b2f07 gfc_free_namespace(gfc_namespace*)
        ../../trunk/gcc/fortran/symbol.c:3525
0x6ad2d3 gfc_free_statement(gfc_code*)
        ../../trunk/gcc/fortran/st.c:124
0x6ad3c9 gfc_free_statements(gfc_code*)
        ../../trunk/gcc/fortran/st.c:272
0x6b2dc8 gfc_free_namespace(gfc_namespace*)
        ../../trunk/gcc/fortran/symbol.c:3527
0x6b33dc gfc_symbol_done_2()
        ../../trunk/gcc/fortran/symbol.c:3573
0x663b88 gfc_done_2()
        ../../trunk/gcc/fortran/misc.c:258
0x677ab5 unexpected_eof
        ../../trunk/gcc/fortran/parse.c:2463
0x67eb24 parse_critical_block
        ../../trunk/gcc/fortran/parse.c:3845
0x67eb24 parse_executable
        ../../trunk/gcc/fortran/parse.c:4671
0x67fb16 parse_progunit
        ../../trunk/gcc/fortran/parse.c:4978
0x67ef33 parse_block_construct
        ../../trunk/gcc/fortran/parse.c:3931
0x67ef33 parse_executable
        ../../trunk/gcc/fortran/parse.c:4645
0x67fb16 parse_progunit
        ../../trunk/gcc/fortran/parse.c:4978
0x67ef33 parse_block_construct
        ../../trunk/gcc/fortran/parse.c:3931
0x67ef33 parse_executable
        ../../trunk/gcc/fortran/parse.c:4645
0x67fb16 parse_progunit
        ../../trunk/gcc/fortran/parse.c:4978
0x681267 gfc_parse_file()
        ../../trunk/gcc/fortran/parse.c:5426
0x6c1535 gfc_be_parse_file
        ../../trunk/gcc/fortran/f95-lang.c:228