am d50225ad: Disable sincos optimization for sincos calls.

* commit 'd50225ad20b4510892dc5f2306b64f04bab6e711':
  Disable sincos optimization for sincos calls.

libm/sincos.c

@@ -27,6 +27,14 @@
 #define _GNU_SOURCE 1
 #include <math.h>
 
+// Disable sincos optimization for all functions in this file,
+// otherwise gcc would generate infinite calls.
+// Refer to gcc PR46926.
+// -fno-builtin-sin or -fno-builtin-cos can disable sincos optimization,
+// but these two options do not work inside optimize pragma in-file.
+// Thus we just enforce -O0 when compiling this file.
+#pragma GCC optimize ("O0")
+
 void  sincos(double x, double *psin, double *pcos)
 {
     *psin = sin(x);