patch 9.0.2180: POSIX function name in exarg causes issues

Problem:  POSIX function name in exarg struct causes issues
          on OpenVMS
Solution: Rename getline member in exarg struct to ea_getline,
          remove isinf() workaround for VMS

There are compilers that do not treat well POSIX functions - like
getline - usage in the structs.

Older VMS compilers could digest this... but the newer OpenVMS compilers
( like VSI C x86-64 X7.4-843 (GEM 50XB9) ) cannot deal with these
structs. This could be limited to getline() that is defined via
getdelim() and might not affect all POSIX functions in general - but
avoiding POSIX function names usage in the structs is a "safe side"
practice without compromising the functionality or the code readability.

The previous OpenVMS X86 port used a workaround limiting the compiler
capabilities using __CRTL_VER_OVERRIDE=80400000
In order to make the OpenVMS port future proof, this pull request
proposes a possible solution.

closes: #13704

Signed-off-by: Zoltan Arpadffy <zoltan.arpadffy@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/Make_vms.mms b/src/Make_vms.mms
index 4c20601..85b825e 100644
--- a/src/Make_vms.mms
+++ b/src/Make_vms.mms
@@ -112,8 +112,8 @@
 CC_DEF  = cc
 PREFIX  = /prefix=all/name=(upper,short)
 OPTIMIZE= /opt
-.IFDEF MMSX86_64 # This is needed because of getline function name used in stucts like ex_cmds.h  
-ARCH_DEF= ,__CRTL_VER_OVERRIDE=80400000
+.IFDEF MMSX86_64
+ARCH_DEF=        # ,__CRTL_VER_OVERRIDE=80400000 
 .ENDIF
 .ENDIF