[Bug cobol/119213] New: gcc/cobol/Make-lang.in: suspicious -DEXEC_LIB with hardcoded lib64

[sjames at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119213

            Bug ID: 119213
           Summary: gcc/cobol/Make-lang.in: suspicious -DEXEC_LIB with
                    hardcoded lib64
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: build
          Severity: normal
          Priority: P3
         Component: cobol
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sjames at gcc dot gnu.org
  Target Milestone: ---

gcc/cobol/Make-lang.in:
```
#
# Note further that we are producing only a 64-bit version of libgcobol.so, so
# it is safe to hard-code the lib64 location.  This obviously has to match the
# installation code in libgcobol/Makefile.in
#
CPPFLAGS =                                      \
 -std=c++14                                     \
 -Iinclude                                      \
 -I$(BINCLUDE)                                  \
 -I$(LIB_INCLUDE)                               \
 -DEXEC_LIB=\"$(prefix)/lib64\"         \
 $(END)
```

Hardcoding lib64 isn't right, despite the comment, because /usr/lib64 doesn't
have to exist. e.g. on musl (which has no multilib), you usually just have
/usr/lib which is 64-bit.