v1.0.0 for hardware-PWM on SAMD21/SAMD51 boards

### Releases v1.0.0

1. Initial coding for **SAMD21/SAMD51 boards** such as `NANO_33_IOT`, `ITSYBITSY_M4`, `SEEED_XIAO_M0`, `SparkFun SAMD51_Thing_Plus`, etc. using
- [Arduino SAMD core](https://github.com/arduino/ArduinoCore-samd)
- [Adafruit SAMD core](https://github.com/adafruit/ArduinoCore-samd)
- [Seeed-Studio SAMD core](https://github.com/Seeed-Studio/ArduinoCore-samd)
- [Sparkfun SAMD core](https://github.com/sparkfun/Arduino_Boards)
- [Industruino SAMD core](https://github.com/Industruino/IndustruinoSAMD)
- [Industruino SAMx core](https://github.com/Industruino/IndustruinoSAMx)

Packages_Patches/Seeeduino/hardware/samd/1.7.7/cores/arduino/Arduino.h

@@ -0,0 +1,181 @@
+/*
+  Arduino.h - Main include file for the Arduino SDK
+  Copyright (c) 2014 Arduino LLC.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#ifndef Arduino_h
+#define Arduino_h
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#define CORE_HAS_LIBB64
+
+typedef bool boolean;
+typedef uint8_t byte;
+typedef uint16_t word;
+
+// some libraries and sketches depend on this AVR stuff,
+// assuming Arduino.h or WProgram.h automatically includes it...
+//
+#include "avr/pgmspace.h"
+#include "avr/interrupt.h"
+#include "avr/dtostrf.h"
+#include "avr/io.h"
+
+#include "binary.h"
+#include "itoa.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+// Include Atmel headers
+#include "sam.h"
+
+#include "wiring_constants.h"
+
+#define clockCyclesPerMicrosecond() ( SystemCoreClock / 1000000L )
+#define clockCyclesToMicroseconds(a) ( ((a) * 1000L) / (SystemCoreClock / 1000L) )
+#define microsecondsToClockCycles(a) ( (a) * (SystemCoreClock / 1000000L) )
+
+void yield( void ) ;
+
+/* system functions */
+int main( void );
+void init( void );
+
+/* sketch */
+void setup( void ) ;
+void loop( void ) ;
+
+int __debug_buf(const char* head, char* buf, int len);
+
+#include "WVariant.h"
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+// The following headers are for C++ only compilation
+#ifdef __cplusplus
+  #include "WCharacter.h"
+  #include "WString.h"
+  #include "Tone.h"
+  #include "WMath.h"
+  #include "HardwareSerial.h"
+  #include "pulse.h"
+#endif
+#include "delay.h"
+#ifdef __cplusplus
+  #include "Uart.h"
+#endif
+
+// Include board variant
+#include "variant.h"
+
+#include "wiring.h"
+#include "wiring_digital.h"
+#include "wiring_analog.h"
+#include "wiring_shift.h"
+#include "wiring_pwm.h"
+#include "WInterrupts.h"
+
+// undefine stdlib's abs if encountered
+#ifdef abs
+  #undef abs
+#endif // abs
+// undefine stdlib's abs if encountered
+#ifdef abs
+  #undef abs
+#endif // abs
+
+#ifdef __cplusplus
+template<class T, class L>
+auto min(const T& a, const L& b) -> decltype((b < a) ? b : a)
+{
+  return (b < a) ? b : a;
+}
+
+template<class T, class L>
+auto max(const T& a, const L& b) -> decltype((b < a) ? b : a)
+{
+  return (a < b) ? b : a;
+}
+#else
+#ifndef min
+#define min(a,b) \
+   ({ __typeof__ (a) _a = (a); \
+       __typeof__ (b) _b = (b); \
+     _a < _b ? _a : _b; })
+#endif
+#ifndef max
+#define max(a,b) \
+   ({ __typeof__ (a) _a = (a); \
+       __typeof__ (b) _b = (b); \
+     _a > _b ? _a : _b; })
+#endif
+#endif
+
+#define abs(x) ((x)>0?(x):-(x))
+#define constrain(amt,low,high) ((amt)<(low)?(low):((amt)>(high)?(high):(amt)))
+#define round(x)     ((x)>=0?(long)((x)+0.5):(long)((x)-0.5))
+#define radians(deg) ((deg)*DEG_TO_RAD)
+#define degrees(rad) ((rad)*RAD_TO_DEG)
+#define sq(x) ((x)*(x))
+
+#define interrupts() __enable_irq()
+#define noInterrupts() __disable_irq()
+#ifndef interruptsStatus
+static inline unsigned char __interruptsStatus(void) __attribute__((always_inline, unused));
+static inline unsigned char __interruptsStatus(void)
+{
+  // See http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0497a/CHDBIBGJ.html
+  return (__get_PRIMASK() ? 0 : 1);
+}
+#define interruptsStatus() __interruptsStatus()
+#endif
+
+#define lowByte(w) ((uint8_t) ((w) & 0xff))
+#define highByte(w) ((uint8_t) ((w) >> 8))
+
+#define bitRead(value, bit) (((value) >> (bit)) & 0x01)
+#define bitSet(value, bit) ((value) |= (1UL << (bit)))
+#define bitClear(value, bit) ((value) &= ~(1UL << (bit)))
+#define bitWrite(value, bit, bitvalue) (bitvalue ? bitSet(value, bit) : bitClear(value, bit))
+
+#define bit(b) (1UL << (b))
+
+#if (ARDUINO_SAMD_VARIANT_COMPLIANCE >= 10606)
+  // Interrupts
+  #define digitalPinToInterrupt(P)   ( P )
+#endif
+
+// USB
+#ifdef USE_TINYUSB
+  #include "Adafruit_TinyUSB_Core.h"
+#else
+  #include "USB/USBDesc.h"
+  #include "USB/USBCore.h"
+  #include "USB/USBAPI.h"
+  #include "USB/USB_host.h"
+#endif
+
+#endif // Arduino_h