machine/esp32s3: use edge-triggered CPU interrupt for GPIO pin interrupts

When SPI is configured via the GPIO Matrix, SPI signal transitions set
GPIO.STATUS bits on the routed pins. With a level-triggered CPU interrupt
(line 8), the ISR re-enters continuously as long as any STATUS bit is
asserted — causing user GPIO callbacks to fire spuriously.

Switch cpuInterruptFromPin to CPU interrupt 10, which is edge-triggered
(level 1) on the Xtensa LX7. This ensures the ISR fires once per GPIO
event rather than looping while SPI is active.

Also move STATUS_W1TC clears to before callback dispatch so that new
GPIO events arriving during handler execution generate a fresh edge, and
add writeINTCLEAR(active) in handleInterrupt to properly acknowledge
edge-triggered CPU interrupt pending bits via the INTCLEAR register.

Fixes GPIO interrupts firing constantly when SPI and pin interrupts are
used together.

Signed-off-by: deadprogram <ron@hybridgroup.com>

src/runtime/interrupt/interrupt_esp32s3.go

@@ -107,6 +107,12 @@ func handleInterrupt() {
 	enabled := readINTENABLE()
 	active := pending & enabled
 
+	// Clear edge-triggered pending bits before dispatching handlers so that
+	// new edges arriving during handler execution are not lost.  Writing to
+	// INTCLEAR is a no-op for level-triggered lines, so this is safe for all
+	// interrupt types.
+	writeINTCLEAR(active)
+
 	for i := firstCPUInt; i <= lastCPUInt; i++ {
 		if active&(1<<uint(i)) != 0 {
 			// callHandlers requires a compile-time constant, so we
@@ -212,6 +218,16 @@ func readINTERRUPT() uint32 {
 	return uint32(device.AsmFull("rsr {}, INTERRUPT", nil))
 }
 
+// writeINTCLEAR writes the INTCLEAR special register (SR 227).
+// Setting bit N clears CPU interrupt N if it is edge-triggered or
+// software-triggered.  Bits corresponding to level-triggered interrupts
+// are ignored by hardware.
+func writeINTCLEAR(val uint32) {
+	device.AsmFull("wsr {val}, INTCLEAR", map[string]interface{}{
+		"val": val,
+	})
+}
+
 // -- Interrupt matrix helpers -----------------------------------------------
 // The ESP32-S3 interrupt matrix has one mapping register per peripheral
 // source.  These are memory-mapped in the INTERRUPT_CORE0 peripheral.