Fix failing Windows tests

Some tests were not written to run on Windows correctly. Compile also
has a bug that caused using the --zip flag to fail on Windows.
iswspace does count the non breaking space as Whiespace on Windows but
not on Unix based systems

Bug: 117156986
Change-Id: I999375162bdfdf86fb25992ee88e2962ab90b577
Test: aapt2_tests and wine aapt2_tests.exe
diff --git a/tools/aapt2/io/ZipArchive.cpp b/tools/aapt2/io/ZipArchive.cpp
index 8e6d713..7d0f6b9 100644
--- a/tools/aapt2/io/ZipArchive.cpp
+++ b/tools/aapt2/io/ZipArchive.cpp
@@ -154,6 +154,13 @@
   return util::make_unique<ZipFileCollectionIterator>(this);
 }
 
+char ZipFileCollection::GetDirSeparator() {
+  // According to the zip file specification, section  4.4.17.1:
+  // "All slashes MUST be forward slashes '/' as opposed to backwards slashes '\' for compatibility
+  // with Amiga and UNIX file systems etc."
+  return '/';
+}
+
 ZipFileCollection::~ZipFileCollection() {
   if (handle_) {
     CloseArchive(handle_);