[compiler-rt] Don't intercept sigaction and signal for CHERI RISCV

This avoids the following errors:

<inline asm>:10:1: error: instruction requires the following: Not Capability Mode
   10 | tail __interceptor_signal@plt
      | ^
<inline asm>:19:1: error: instruction requires the following: Not Capability Mode
   19 | tail __interceptor_sigaction@plt
      |

Author: RoundofThree

compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h

@@ -498,7 +498,7 @@
 #define SANITIZER_INTERCEPT_WCSLEN 1
 #define SANITIZER_INTERCEPT_WCSCAT SI_POSIX
 #define SANITIZER_INTERCEPT_WCSDUP SI_POSIX
-#define SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION (!SI_WINDOWS && SI_NOT_FUCHSIA)
+#define SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION (!SI_WINDOWS && SI_NOT_FUCHSIA && !SANITIZER_RISCV64)
 #define SANITIZER_INTERCEPT_BSD_SIGNAL SI_ANDROID
 
 #define SANITIZER_INTERCEPT_ACCT (SI_NETBSD || SI_FREEBSD)