Assorted portability enhancements (#1800)

* Introduce some Platform calls for managing dynamic libraries

* Add Platform::WriteFATSectors

* Introduce some Platform calls for managing dynamic libraries

* Add Platform::WriteFATSectors

* Change includes of "../types.h" to "types.h"

- Makes it easier to directly include these headers in downstream projects

* Change an include of "../Wifi.h" to "Wifi.h"

* Allow CommonFuncs.cpp to compile on Android

* Tidy up some logging calls

- Use Platform::Log in LAN_Socket.cpp
- Soften some warnings to Debug logs (since they don't necessarily represent problems)

* Add Platform::EnterGBAMode

- Gracefully stop the emulator if trying to enter GBA mode

* Soften some logs that most players won't care about

* Soften some more logs

* Introduce Platform wrappers for file operations

* Fix pointer spacing

* Fix more style nits

* Log the errno when ftruncate fails

* Fix FileSeek offset argument

- With an s32 offset, we couldn't access files larger than 2GB

* Revise Platform::StopEmu to address feedback

- Remove Platform::EnterGBAMode in favor of adding a reason to Platform::StopEmu
- Also rename Platform::StopEmu to Platform::SignalStop
- Add an optional argument to NDS::Stop
- Use the new argument everywhere that the console stops itself

* Rename FileGetString to FileReadLine

- It conveys the meaning better

* Rename FileSeekOrigin::Set to Start

- It conveys the meaning better

* Change definition of FileGetString to FileReadLine

- Oops, almost forgot it

* Rename FlushFile to FileFlush

- To remain consistent with the other File functions

* Add a FileType usage

* Fix line break in FileSeekOrigin

* Document Platform::DeInit

* Clarify that StopReason::Unknown doesn't always mean an error

* Move and document FileType::HostFile

* Remove Platform::OpenDataFile

- Nothing currently uses it

* Refactor Platform::OpenFile and Platform::OpenLocalFile to accept a FileMode enum instead of a string

- The enum is converted to fopen flags under the hood
- The file type is used to decide whether to add the "b" flag
- Some helper functions are exposed for the benefit of consistent behavior among frontends
- Equivalent behavior is maintained

* Fix a tab that should be spaces

* Use Windows' 64-bit implementations of fseek/ftell

* Move Platform::IsBinaryFile to Platform.cpp

- It could vary by frontend

* Remove an unused FileType

* Rename an enum constant

* Document various Platform items

* Use Platform::DynamicLibrary to load libandroid

- And clean it up at the end

* Fix a typo

* Pass the correct filetype to FATStorage

- Since it can be used for DSI NAND images or for SD cards

* Remove Platform::FileType

src/frontend/qt_sdl/LAN_Socket.cpp

@@ -24,6 +24,7 @@
 #include "Wifi.h"
 #include "LAN_Socket.h"
 #include "FIFO.h"
+#include "Platform.h"
 
 #include <slirp/libslirp.h>
 
@@ -40,6 +41,9 @@
 namespace LAN_Socket
 {
 
+using Platform::Log;
+using Platform::LogLevel;
+
 const u32 kSubnet   = 0x0A400000;
 const u32 kServerIP = kSubnet | 0x01;
 const u32 kDNSIP    = kSubnet | 0x02;
@@ -87,7 +91,7 @@ void RXEnqueue(const void* buf, int len)
 
     if (!RXBuffer.CanFit(totallen >> 2))
     {
-        printf("slirp: !! NOT ENOUGH SPACE IN RX BUFFER\n");
+        Log(LogLevel::Warn, "slirp: !! NOT ENOUGH SPACE IN RX BUFFER\n");
         return;
     }
 
@@ -101,11 +105,11 @@ ssize_t SlirpCbSendPacket(const void* buf, size_t len, void* opaque)
 {
     if (len > 2048)
     {
-        printf("slirp: packet too big (%zu)\n", len);
+        Log(LogLevel::Warn, "slirp: packet too big (%zu)\n", len);
         return 0;
     }
 
-    printf("slirp: response packet of %zu bytes, type %04X\n", len, ntohs(((u16*)buf)[6]));
+    Log(LogLevel::Debug, "slirp: response packet of %zu bytes, type %04X\n", len, ntohs(((u16*)buf)[6]));
 
     RXEnqueue(buf, len);
 
@@ -114,7 +118,7 @@ ssize_t SlirpCbSendPacket(const void* buf, size_t len, void* opaque)
 
 void SlirpCbGuestError(const char* msg, void* opaque)
 {
-    printf("SLIRP: error: %s\n", msg);
+    Log(LogLevel::Error, "SLIRP: error: %s\n", msg);
 }
 
 int64_t SlirpCbClockGetNS(void* opaque)
@@ -139,7 +143,7 @@ void SlirpCbTimerMod(void* timer, int64_t expire_time, void* opaque)
 
 void SlirpCbRegisterPollFD(int fd, void* opaque)
 {
-    printf("Slirp: register poll FD %d\n", fd);
+    Log(LogLevel::Debug, "Slirp: register poll FD %d\n", fd);
 
     /*if (FDListSize >= FDListMax)
     {
@@ -158,7 +162,7 @@ void SlirpCbRegisterPollFD(int fd, void* opaque)
 
 void SlirpCbUnregisterPollFD(int fd, void* opaque)
 {
-    printf("Slirp: unregister poll FD %d\n", fd);
+    Log(LogLevel::Debug, "Slirp: unregister poll FD %d\n", fd);
 
     /*if (FDListSize < 1)
     {
@@ -178,7 +182,7 @@ void SlirpCbUnregisterPollFD(int fd, void* opaque)
 
 void SlirpCbNotify(void* opaque)
 {
-    printf("Slirp: notify???\n");
+    Log(LogLevel::Debug, "Slirp: notify???\n");
 }
 
 SlirpCb cb =
@@ -283,7 +287,7 @@ void HandleDNSFrame(u8* data, int len)
     u16 numauth = ntohs(*(u16*)&dnsbody[8]);
     u16 numadd = ntohs(*(u16*)&dnsbody[10]);
 
-    printf("DNS: ID=%04X, flags=%04X, Q=%d, A=%d, auth=%d, add=%d\n",
+    Log(LogLevel::Debug, "DNS: ID=%04X, flags=%04X, Q=%d, A=%d, auth=%d, add=%d\n",
            id, flags, numquestions, numanswers, numauth, numadd);
 
     // for now we only take 'simple' DNS requests
@@ -429,7 +433,7 @@ int SendPacket(u8* data, int len)
 
     if (len > 2048)
     {
-        printf("LAN_SendPacket: error: packet too long (%d)\n", len);
+        Log(LogLevel::Error, "LAN_SendPacket: error: packet too long (%d)\n", len);
         return 0;
     }
 
@@ -461,7 +465,7 @@ int SlirpCbAddPoll(int fd, int events, void* opaque)
 {
     if (PollListSize >= PollListMax)
     {
-        printf("slirp: POLL LIST FULL\n");
+        Log(LogLevel::Error, "slirp: POLL LIST FULL\n");
         return -1;
     }