switch experimental::fs to std::fs

std::filesystem was added to C++17 and is well supported now.  Remove
the older std::experimental::filesystem usage.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I6d1ef0f3ac02954ddbffc332393fa11930dffad7
diff --git a/vpnor/test/Makefile.am.include b/vpnor/test/Makefile.am.include
index 71a1517..dbbf3fc 100644
--- a/vpnor/test/Makefile.am.include
+++ b/vpnor/test/Makefile.am.include
@@ -11,7 +11,7 @@
 	vpnor/table.cpp \
 	%reldir%/tmpd.cpp
 
-VPNOR_LDADD = -lstdc++fs \
+VPNOR_LDADD = \
 	$(SDBUSPLUS_LIBS) \
 	$(PHOSPHOR_LOGGING_LIBS) \
 	$(PHOSPHOR_DBUS_INTERFACES_LIBS)
diff --git a/vpnor/test/create_aligned_window.cpp b/vpnor/test/create_aligned_window.cpp
index 910e7c5..82f035d 100644
--- a/vpnor/test/create_aligned_window.cpp
+++ b/vpnor/test/create_aligned_window.cpp
@@ -12,7 +12,7 @@
 
 #include <cassert>
 #include <cstring>
-#include <experimental/filesystem>
+#include <filesystem>
 #include <fstream>
 #include <vector>
 
diff --git a/vpnor/test/create_read_window_partition_exists.cpp b/vpnor/test/create_read_window_partition_exists.cpp
index 5469615..b32e2d8 100644
--- a/vpnor/test/create_read_window_partition_exists.cpp
+++ b/vpnor/test/create_read_window_partition_exists.cpp
@@ -12,7 +12,7 @@
 
 #include <cassert>
 #include <cstring>
-#include <experimental/filesystem>
+#include <filesystem>
 #include <fstream>
 #include <vector>
 
diff --git a/vpnor/test/create_read_window_remap.cpp b/vpnor/test/create_read_window_remap.cpp
index 5e25412..2f27be1 100644
--- a/vpnor/test/create_read_window_remap.cpp
+++ b/vpnor/test/create_read_window_remap.cpp
@@ -12,7 +12,7 @@
 
 #include <cassert>
 #include <cstring>
-#include <experimental/filesystem>
+#include <filesystem>
 #include <fstream>
 #include <vector>
 
diff --git a/vpnor/test/create_read_window_size.cpp b/vpnor/test/create_read_window_size.cpp
index 17240c9..f12a6c8 100644
--- a/vpnor/test/create_read_window_size.cpp
+++ b/vpnor/test/create_read_window_size.cpp
@@ -11,7 +11,7 @@
 #include "vpnor/test/tmpd.hpp"
 
 #include <cassert>
-#include <experimental/filesystem>
+#include <filesystem>
 
 #include "vpnor/backend.h"
 
diff --git a/vpnor/test/create_read_window_straddle_partitions.cpp b/vpnor/test/create_read_window_straddle_partitions.cpp
index 7b09ff6..f71acf8 100644
--- a/vpnor/test/create_read_window_straddle_partitions.cpp
+++ b/vpnor/test/create_read_window_straddle_partitions.cpp
@@ -45,7 +45,7 @@
 int main()
 {
     namespace test = openpower::virtual_pnor::test;
-    namespace fs = std::experimental::filesystem;
+    namespace fs = std::filesystem;
 
     struct mbox_context* ctx;
 
diff --git a/vpnor/test/tmpd.cpp b/vpnor/test/tmpd.cpp
index 917fb71..699c659 100644
--- a/vpnor/test/tmpd.cpp
+++ b/vpnor/test/tmpd.cpp
@@ -10,7 +10,7 @@
 namespace test
 {
 
-namespace fs = std::experimental::filesystem;
+namespace fs = std::filesystem;
 
 size_t VpnorRoot::write(const std::string& name, const void* data, size_t len)
 {
diff --git a/vpnor/test/tmpd.hpp b/vpnor/test/tmpd.hpp
index ae6da9e..38fb428 100644
--- a/vpnor/test/tmpd.hpp
+++ b/vpnor/test/tmpd.hpp
@@ -12,7 +12,7 @@
 
 #include <cassert>
 #include <cstring>
-#include <experimental/filesystem>
+#include <filesystem>
 #include <fstream>
 #include <vector>
 
@@ -23,7 +23,7 @@
 namespace test
 {
 
-namespace fs = std::experimental::filesystem;
+namespace fs = std::filesystem;
 
 class VpnorRoot
 {
diff --git a/vpnor/test/toc_missing_file.cpp b/vpnor/test/toc_missing_file.cpp
index 2face11..d573fe1 100644
--- a/vpnor/test/toc_missing_file.cpp
+++ b/vpnor/test/toc_missing_file.cpp
@@ -29,7 +29,7 @@
 int main()
 {
     namespace test = openpower::virtual_pnor::test;
-    namespace fs = std::experimental::filesystem;
+    namespace fs = std::filesystem;
     namespace vpnor = openpower::virtual_pnor;
 
     struct mbox_context* ctx;
diff --git a/vpnor/test/write_patch.cpp b/vpnor/test/write_patch.cpp
index 4a200c0..49d1d1a 100644
--- a/vpnor/test/write_patch.cpp
+++ b/vpnor/test/write_patch.cpp
@@ -18,7 +18,7 @@
 #include <unistd.h>
 
 #include <cassert>
-#include <experimental/filesystem>
+#include <filesystem>
 
 static constexpr auto BLOCK_SIZE = 0x1000;
 static constexpr auto DATA_SIZE = 8;
@@ -32,7 +32,7 @@
 
 int main(void)
 {
-    namespace fs = std::experimental::filesystem;
+    namespace fs = std::filesystem;
     namespace test = openpower::virtual_pnor::test;
 
     struct mbox_context _ctx, *ctx = &_ctx;
diff --git a/vpnor/test/write_patch_resize.cpp b/vpnor/test/write_patch_resize.cpp
index 38effd6..56d7423 100644
--- a/vpnor/test/write_patch_resize.cpp
+++ b/vpnor/test/write_patch_resize.cpp
@@ -19,7 +19,7 @@
 #include <unistd.h>
 
 #include <cassert>
-#include <experimental/filesystem>
+#include <filesystem>
 
 static constexpr auto BLOCK_SIZE = 0x1000;
 static constexpr auto PART_SIZE = BLOCK_SIZE;
@@ -32,7 +32,7 @@
 
 int main(void)
 {
-    namespace fs = std::experimental::filesystem;
+    namespace fs = std::filesystem;
     namespace test = openpower::virtual_pnor::test;
 
     struct mbox_context _ctx, *ctx = &_ctx;
diff --git a/vpnor/test/write_prsv.cpp b/vpnor/test/write_prsv.cpp
index 134a98e..d959329 100644
--- a/vpnor/test/write_prsv.cpp
+++ b/vpnor/test/write_prsv.cpp
@@ -27,7 +27,7 @@
 
 int main(void)
 {
-    namespace fs = std::experimental::filesystem;
+    namespace fs = std::filesystem;
 
     struct mbox_context _ctx, *ctx = &_ctx;
     uint8_t src[8];
diff --git a/vpnor/test/write_ro.cpp b/vpnor/test/write_ro.cpp
index 5965ebf..b125236 100644
--- a/vpnor/test/write_ro.cpp
+++ b/vpnor/test/write_ro.cpp
@@ -26,7 +26,7 @@
 
 int main(void)
 {
-    namespace fs = std::experimental::filesystem;
+    namespace fs = std::filesystem;
     namespace test = openpower::virtual_pnor::test;
 
     struct mbox_context _ctx, *ctx = &_ctx;
diff --git a/vpnor/test/write_rw.cpp b/vpnor/test/write_rw.cpp
index cf9bf7b..548f7d9 100644
--- a/vpnor/test/write_rw.cpp
+++ b/vpnor/test/write_rw.cpp
@@ -26,7 +26,7 @@
 
 int main(void)
 {
-    namespace fs = std::experimental::filesystem;
+    namespace fs = std::filesystem;
     namespace test = openpower::virtual_pnor::test;
 
     struct mbox_context _ctx, *ctx = &_ctx;