[MemProf] Make test more resilient to cpu scheduling

[tejohnson]

Summary

Loosen up the matching so that occasional cpu migrations don't break the
test. This showed up occasionally in internal testing.

[snehasish]

lgtm

compiler-rt/test/memprof/TestCases/test_merge_mib.cpp

 // Check that merging of MIB info (min/max size and access counts specifically)
 // is done correctly.
 
 // RUN: %clangxx_memprof -O0 %s -o %t
 // RUN: %env_memprof_opts=print_text=true:log_path=stderr %run %t 2>&1 | FileCheck %s
 
 // This is actually:
 //  Memory allocation stack id = STACKID
 //   alloc_count 2, size (ave/min/max) 60.00 / 40 / 80
 // but we need to look for them in the same CHECK to get the correct STACKID.
 // CHECK:  Memory allocation stack id = [[STACKID:[0-9]+]]{{[[:space:]].*}}alloc_count 2, size (ave/min/max) 60.00 / 40 / 80
 // CHECK-NEXT:  access_count (ave/min/max): 30.00 / 20 / 40
 // Unfortunately there is not a reliable way to check the ave/min/max lifetime.
 // CHECK-NEXT:  lifetime (ave/min/max):
-// CHECK-NEXT:  num migrated: {{[0-1]}}, num lifetime overlaps: 0, num same alloc cpu: 1, num same dealloc_cpu: 1
+// CHECK-NEXT:  num migrated: {{[0-1]}}, num lifetime overlaps: 0, num same alloc cpu: {{[0-1]}}, num same dealloc_cpu: {{[0-1]}}
 // CHECK: Stack for id [[STACKID]]:
 // CHECK-NEXT: #0 {{.*}} in operator new
 // CHECK-NEXT: #1 {{.*}} in main {{.*}}:[[@LINE+7]]
 
 #include <stdio.h>
 #include <stdlib.h>
 
 int main() {