fix #16265; fix #13999 (HCR on OSX); cgen now does not line wrap string litterals (#16329)

* fix #16265: cgen now does not line wrap string litterals which, in combination with other hacks, caused a really obscure looking bug

* fix #13999; nimhcr_integration.nim now works for osx

* try to make appveyor CI disappear

* disable openbsd + add diagnostic for openbsd

* enable for openbsd

* PTEMP

* re-disable openbsd

tests/dll/nimhcr_integration.nim

@@ -1,7 +1,5 @@
 discard """
   disabled: "openbsd"
-  disabled: "netbsd"
-  disabled: "macosx"
   output: '''
 main: HELLO!
 main: hasAnyModuleChanged? true
@@ -56,6 +54,20 @@ done
 '''
 """
 
+#[
+xxx disabled: "openbsd" because it would otherwise give:
+/home/build/Nim/lib/nimhcr.nim(532) hcrInit
+/home/build/Nim/lib/nimhcr.nim(503) initModules
+/home/build/Nim/lib/nimhcr.nim(463) initPointerData
+/home/build/Nim/lib/nimhcr.nim(346) hcrRegisterProc
+/home/build/Nim/lib/pure/reservedmem.nim(223) setLen
+/home/build/Nim/lib/pure/reservedmem.nim(97) setLen
+/home/build/Nim/lib/pure/includes/oserr.nim(94) raiseOSError
+Error: unhandled exception: Not supported [OSError]
+
+After instrumenting code, the stacktrace actually points to the call to `check mprotect`
+]#
+
 ## This is perhaps the most complex test in the nim test suite - calling the
 ## compiler on the file itself with the same set or arguments and reloading
 ## parts of the program at runtime! In the same folder there are a few modules
@@ -100,6 +112,7 @@ proc compileReloadExecute() =
   #   binary triggers rebuilding itself here it shouldn't rebuild the main module -
   #   that would lead to replacing the main binary executable which is running!
   let cmd = commandLineParams()[0..^1].join(" ").replace(" --forceBuild")
+  doAssert cmd.len > 0
   let (stdout, exitcode) = execCmdEx(cmd)
   if exitcode != 0:
     echo "COMPILATION ERROR!"