[MCOMPILER-425] Compiler argument with newline treated as multiple arguments in fork mode

**[David Phillips](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=electrum)** opened **[MCOMPILER-425](https://issues.apache.org/jira/browse/MCOMPILER-425?redirect=false)** and commented

In the below example, we want to pass the second argument as a single argument to the compiler, but we add newlines in the XML for readability. This works correctly when not forking, but when forking, the argument is treated as multiple arguments.

```xml

true

-XDcompilePolicy=simple

-Xplugin:ErrorProne
-Xep:ObjectToString:ERROR




com.google.errorprone
error_prone_core
2.4.0

```

---

**Affects:** 3.8.1

**Issue Links:**
- [MCOMPILER-572](https://issues.apache.org/jira/browse/MCOMPILER-572) Multi-line \ does not work on Windows when forked

Reproduce the XML configuration with fork enabled and compare how the multiline is passed in forked and non-forked modes. Review the related MCOMPILER-572 report for the Windows case; done means the multiline value remains one compiler argument when forked, including on Windows.

Written by the indexing model from the issue text.