Compiler.Common.tmpName should not use tmpnam

[wchresta]

The module Compiler.Common exposes the tmpName function creating a new temporary file.

https://github.com/edwinb/Idris2/blob/65db4fbf961cbdd36f10a9a75e7c3311b91f5585/src/Compiler/Common.idr#L116-L119

According to GNU manpage 3 for tmpnam(3), this function should never be used:

Never use this function. Use mkstemp(3) or tmpfile(3) instead.

Expected Behavior

Compiler.Common.tmpName is not implemented using tmpnam

Observed Behavior

Compiler.Common.tmpName is implemented using tmpnam

[youlam]

tmpnam also appears in dist/idris2.c, line 239664 in my distribution. Gave me this warning

clang   idris2.c -o idris2 -I rts -L rts -lidris_rts -lgmp -lm
    idris2.c:239664:22: warning: 'tmpnam' is deprecated: This function is provided for compatibility reasons only. Due to security concerns inherent in the design of tmpnam(3), it is highly recommended that you use mkstemp(3) instead.
[-Wdeprecated-declarations]
RVAL = MKSTR(vm, tmpnam(GETPTR(LOC(1))));
                 ^
/usr/include/stdio.h:277:7: note: 'tmpnam' has been explicitly marked deprecated here

char *tmpnam(char *);`