various Z2Audio / JAudio debug cleanup (#2876)

* some JAudio work

* audio cleanup checkpoint

* checkpoint more audio cleanup

* fix symbols

* more z2 cleanup

* fix regression

* fix build

* some fixes

src/PowerPC_EABI_Support/MSL/MSL_C/MSL_Common/Include/math.h

@@ -34,6 +34,10 @@ double cos(double);
 float cosf(float);
 double exp(double);
 
+inline float expf(float x) {
+    return exp(x);
+}
+
 extern double __frsqrte(double);
 extern float __fres(float);