[sanitizer_common] Heed __ndbl_ prefix for 32-bit Linux/sparc64 interceptors

When ASan testing is enabled on SPARC as per PR llvm#107405, a couple of tests
`FAIL` on Linux/sparc64:
```
  AddressSanitizer-sparc-linux :: TestCases/printf-2.c
  AddressSanitizer-sparc-linux :: TestCases/printf-3.c
  AddressSanitizer-sparc-linux :: TestCases/printf-4.c
  AddressSanitizer-sparc-linux :: TestCases/printf-5.c

  SanitizerCommon-asan-sparc-Linux :: Linux/unexpected_format_specifier_test.cpp
```
It turns out the interceptors aren't used since on Linux/sparc64 `double`
and `long double` are the same, and a couple of `stdio` functions are
prefixed with `__nldbl_` (no long double) accordingly.

This patch handles this.

Tested on `sparc64-unknown-linux-gnu`.

Author: rorth

compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc

@@ -127,6 +127,39 @@ extern const short *_toupper_tab_;
 extern const short *_tolower_tab_;
 #endif
 
+#if SANITIZER_LINUX && SANITIZER_SPARC32
+// On 32-bit Linux/sparc64, double and long double are identical and glibc
+// uses a __nldbl_ (no long double) prefix for various stdio functions.
+#  define __isoc23_fscanf __nldbl___isoc23_fscanf
+#  define __isoc23_scanf __nldbl___isoc23_scanf
+#  define __isoc23_sscanf __nldbl___isoc23_sscanf
+#  define __isoc23_vfscanf __nldbl___isoc23_vfscanf
+#  define __isoc23_vscanf __nldbl___isoc23_vscanf
+#  define __isoc23_vsscanf __nldbl___isoc23_vsscanf
+#  define __isoc99_fscanf __nldbl___isoc99_fscanf
+#  define __isoc99_scanf __nldbl___isoc99_scanf
+#  define __isoc99_sscanf __nldbl___isoc99_sscanf
+#  define __isoc99_vfscanf __nldbl___isoc99_vfscanf
+#  define __isoc99_vscanf __nldbl___isoc99_vscanf
+#  define __isoc99_vsscanf __nldbl___isoc99_vsscanf
+#  define asprintf __nldbl_asprintf
+#  define fprintf __nldbl_fprintf
+#  define fscanf __nldbl_fscanf
+#  define printf __nldbl_printf
+#  define scanf __nldbl_scanf
+#  define snprintf __nldbl_snprintf
+#  define sprintf __nldbl_sprintf
+#  define sscanf __nldbl_sscanf
+#  define vasprintf __nldbl_vasprintf
+#  define vfprintf __nldbl_vfprintf
+#  define vfscanf __nldbl_vfscanf
+#  define vprintf __nldbl_vprintf
+#  define vscanf __nldbl_vscanf
+#  define vsnprintf __nldbl_vsnprintf
+#  define vsprintf __nldbl_vsprintf
+#  define vsscanf __nldbl_vsscanf
+#endif
+
 #if SANITIZER_MUSL && \
   (defined(__i386__) || defined(__arm__) || SANITIZER_MIPS32 || SANITIZER_PPC32)
 // musl 1.2.0 on existing 32-bit architectures uses new symbol names for the