[Bug fortran/102043] [9/10/11/12 Regression] Wrong array types used for negative stride accesses, gfortran.dg/vector_subscript_1.f90 FAILs

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102043

--- Comment #44 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Mikael Morin <mikael@gcc.gnu.org>:

https://gcc.gnu.org/g:89ca0fffa48b799b228beee48a16e26e24d8e199

commit r12-8227-g89ca0fffa48b799b228beee48a16e26e24d8e199
Author: Mikael Morin <mikael@gcc.gnu.org>
Date:   Fri Apr 22 22:52:12 2022 +0200

    fortran: Pre-evaluate string pointers. [PR102043]

    This avoids a regression on deferred_character_23.f90 later in the
    patch series when array references are rewritten to use pointer
    arithmetic.

    The problem is a SAVE_EXPR tree as TYPE_SIZE_UNIT of one array element
    type, which is used by the pointer arithmetic expressions.  As these
    expressions appear in both branches of an if-then-else block, the tree
    is lowered to a variable in one of the branches but itâs used in both
    branches, which is invalid middle-end code.

    This change pre-evaluates the array references or pointer arithmetics
    to variables before the if-then-else block, so that the SAVE_EXPR are
    expanded to variables in the parent scope of the if-then-else block,
    and expressions referencing the variables remain valid in both
    branches.

            PR fortran/102043

    gcc/fortran/ChangeLog:
            * trans-expr.cc: Pre-evaluate src and dest to variables
            before using them.

    gcc/testsuite/ChangeLog:
            * gfortran.dg/dependency_49.f90: Update variable occurence
            count.