switch to ocaml-406

[bobzhang]

TODO:

• help upgrade super-errors
• figure out a way to maintain history

The CI failed due to some .npmignore issues, should we vendor a tar file instead??

[bobzhang]

snapshot needs something to fix:

jscomp>time ninja -C ../lib ninja: Entering directory `../lib' [1/6] Making reactjs_jsx_ppx_2.exe FAILED: reactjs_jsx_ppx_2.exe ocamlopt.opt -g -w -a ../jscomp/stubs/ext_basic_hash_stubs.c -w -40-30 -no-alias-deps -I +compiler-libs ocamlcommon.cmxa -o reactjs_jsx_ppx_2.exe reactjs_jsx_ppx_v2.mli reactjs_jsx_ppx_v2.ml File "reactjs_jsx_ppx_v2.ml", line 50, characters 60-81: Error: The constructor Asttypes.Const_string belongs to the variant type Asttypes.constant but a constructor was expected belonging to the variant type Parsetree.constant [2/6] Making bsppx.exe FAILED: bsppx.exe ocamlopt.opt -g -w -a ../jscomp/stubs/ext_basic_hash_stubs.c -o bsppx.exe bsppx.mli bsppx.ml File "clflags.ml", line 162, characters 5-23: Error: Unbound value Config.safe_string [3/6] Making refmt.exe FAILED: refmt.exe ocamlopt.opt -g -w -a ../jscomp/stubs/ext_basic_hash_stubs.c -w -40-30 -no-alias-deps -I +compiler-libs ocamlcommon.cmxa -o refmt.exe refmt_main3.mli refmt_main3.ml File "src/ast_402.ml", line 87, characters 2-152: Error: This variant or record definition does not match that of type Parsetree.payload Fields number 2 have different names, PSig and PTyp. [5/6] Making bsc.exe FAILED: bsc.exe ocamlopt.opt -g -w -a ../jscomp/stubs/ext_basic_hash_stubs.c -o bsc.exe whole_compiler.mli whole_compiler.ml File "clflags.ml", line 162, characters 5-23: Error: Unbound value Config.safe_string [6/6] Making bsb.exe ninja: build stopped: subcommand failed. real 0m1.181s user 0m2.953s sys 0m0.373s 

[bobzhang]

Seems only reason specific exe is broken

jscomp>ls ../lib/*.exe ../lib/bsb.exe ../lib/bsc.exe ../lib/bsb_helper.exe ../lib/bsppx.exe