A9 analogRead(PureAnalogPin) issue with M4 core

analogRead(A9) generates an undefined reference to `analogRead(PureAnalogPin)' error when compiled for the M4 core.
Setup: Giga R1 board library: 4.1.5

Sketch:

```
#include "Arduino.h"
#include "RPC.h"

#define SERVO_POT_1 A9

void setup() {
RPC.begin();
analogReadResolution(16); //GIGA has 16 bit ADC (0-65535)
}

void loop() {
int temp = analogRead(SERVO_POT_1);
}

```

Error:

Error message:
C:...\AppData\Local\Temp\arduino\sketches\D2129B132D44D2F5F57EC30CA80C2E2B\sketch\sketch_jul25a.ino.cpp.o: In function loop': C:\...\AppData\Local\Temp\.arduinoIDE-unsaved2024625-43476-ja9cee.pq8d\sketch_jul25a/sketch_jul25a.ino:20: undefined reference to A9'
C:...\AppData\Local\Temp.arduinoIDE-unsaved2024625-43476-ja9cee.pq8d\sketch_jul25a/sketch_jul25a.ino:20: undefined reference to `analogRead(PureAnalogPin)'
collect2.exe: error: ld returned 1 exit status

Using library RPC at version 1.0 in folder: C:...\AppData\Local\Arduino15\packages\arduino\hardware\mbed_giga\4.1.5\libraries\RPC
Using library rpclib at version 1.0.0 in folder: C:...\AppData\Local\Arduino15\packages\arduino\hardware\mbed_giga\4.1.5\libraries\rpclib
Using library openamp at version 1.0 in folder: C:...\AppData\Local\Arduino15\packages\arduino\hardware\mbed_giga\4.1.5\libraries\openamp_arduino
exit status 1

Compilation error: exit status 1

Any ideas?

Reproduce the supplied sketch on a Giga R1 using the M4 core and library version 4.1.5, focusing on the analogRead(A9) linker error for analogRead(PureAnalogPin). Trace the M4 analogRead entry point and verify that the sketch compiles and reads A9 successfully when the fix is complete.

Written by the indexing model from the issue text.