[PGO] Sync InstrProfData.inc from llvm to compiler-rt (#99930)

Sync InstrProfData.inc from llvm to compiler-rt. The difference was
introduced from #69535.

Author: xur-llvm

compiler-rt/include/profile/InstrProfData.inc

@@ -739,6 +739,7 @@ serializeValueProfDataFrom(ValueProfRecordClosure *Closure,
 #define INSTR_PROF_PROFILE_RUNTIME_VAR __llvm_profile_runtime
 #define INSTR_PROF_PROFILE_COUNTER_BIAS_VAR __llvm_profile_counter_bias
 #define INSTR_PROF_PROFILE_SET_TIMESTAMP __llvm_profile_set_timestamp
+#define INSTR_PROF_PROFILE_SAMPLING_VAR __llvm_profile_sampling
 
 /* The variable that holds the name of the profile data
  * specified via command line. */