rename __environ so it is compatible with static linking #2988
Description
Building fish-shell against musl I get the following:
x86_64-musl-linux-g++ -static -L/test/lib64 -I/test/include -D_LARGEFILE_SOURCE=1 -D_FILE_OFFSET_BITS=64 -fno-exceptions -Wall -Wno-sign-compare -Ipcre2-10.21/src -iquote. -iquote./src/ -DLOCALEDIR=\"/test/share/locale\" -DPREFIX=L\"/test\" -DDATADIR=L\"/test/share\" -DSYSCONFDIR=L\"/test/etc\" -DBINDIR=L\"/test/bin\" -DDOCDIR=L\"/test/share/doc/fish\" -DFISH_BUILD_VERSION=\"2.3b1\"
-rdynamic obj/function.o obj/builtin.o obj/complete.o obj/env.o obj/exec.o obj/expand.o obj/highlight.o obj/history.o obj/kill.o obj/parser.o obj/proc.o obj/reader.o obj/sanity.o obj/tokenizer.o obj/wildcard.o obj/wgetopt.o obj/wutil.o obj/input.o obj/output.o obj/intern.o obj/env_universal_common.o obj/input_common.o obj/event.o obj/signal.o obj/io.o obj/parse_util.o obj/common.o obj/screen.o obj/path.o obj/autoload.o obj/parser_keywords.o obj/iothread.o obj/color.o obj/postfork.o obj/builtin_string.o obj/builtin_test.o obj/parse_tree.o obj/parse_productions.o obj/parse_execution.o obj/pager.o obj/utf8.o obj/fish_version.o obj/wcstringutil.o obj/fish.o -lncursesw -Lpcre2-10.21/.libs -lpcre2-32 -o fish
/test/bin/../lib/gcc/x86_64-linux-musl/5.3.0/../../../../x86_64-linux-musl/lib/libc.a(__environ.o):(.bss+0x0): multiple definition of `__environ'
obj/common.o:(.bss+0x0): first defined here
collect2: error: ld returned 1 exit status
make: *** [fish] Error 1I have made the changes in the source to get passed this but before I make a PR, is there a reason fish-shell uses __environ instread of something like __environ_?