Use Profile::Sample::GuardedStatus for guarded_status instead of int.

This is the correct type and uses only 1 byte instead of 4. We can then
group `guarded_status` and `allocation_type` into the padding after
`allocation_time` to save 8 bytes.

Cleanup the type casting that is no longer needed.

Before:
struct tcmalloc::tcmalloc_internal::StackTrace needs 7 bytes of padding, non-tail padding is 7 (fields: 18 padded fields: 2) total_size: 616

padding	size	alignment	| Field name
	8	8	| sampled_alloc_handle
	8	8	| proxy
	8	8	| requested_size
	8	8	| requested_alignment
	8	8	| allocated_size
	1	1	| requested_size_returning
	1	1	| access_hint
	1	1	| cold_allocated
	1	1	| has_context
	4	4	| static_initialization_depth
	8	8	| weight
4	12	4	| allocation_time
	8	8	| span_start_address
	8	8	| census_handle
	4	4	| guarded_status
3	1	1	| allocation_type
	8	8	| depth
	512	8	| stack

After:
struct tcmalloc::tcmalloc_internal::StackTrace needs 2 bytes of padding, non-tail padding is 2 (fields: 18 padded fields: 1) total_size: 608

padding	size	alignment	| Field name
	8	8	| sampled_alloc_handle
	8	8	| proxy
	8	8	| requested_size
	8	8	| requested_alignment
	8	8	| allocated_size
	1	1	| requested_size_returning
	1	1	| access_hint
	1	1	| cold_allocated
	1	1	| has_context
	4	4	| static_initialization_depth
	8	8	| weight
	12	4	| allocation_time
	1	1	| guarded_status
2	1	1	| allocation_type
	8	8	| span_start_address
	8	8	| census_handle
	8	8	| depth
	512	8	| stack

PiperOrigin-RevId: 716195113
Change-Id: I766ba0f572c5ebdfc891065ce75aca767b9e2a41

Author: Ken Steele

tcmalloc/allocation_sampling.h

@@ -191,7 +191,7 @@ SampleifyAllocation(Static& state, Policy policy, size_t requested_size,
       1;
   stack_trace.span_start_address = span->start_address();
   stack_trace.allocation_time = absl::Now();
-  stack_trace.guarded_status = static_cast<int>(alloc_with_status.status);
+  stack_trace.guarded_status = alloc_with_status.status;
   stack_trace.allocation_type = policy.allocation_type();
 
   // How many allocations does this sample represent, given the sampling

tcmalloc/internal/logging.h

@@ -87,18 +87,16 @@ struct StackTrace {
   // Timestamp of allocation.
   absl::Time allocation_time;
 
+  Profile::Sample::GuardedStatus guarded_status;
+
+  // How the memory was allocated (new/malloc/etc.)
+  Profile::Sample::AllocationType allocation_type;
+
   // If not nullptr, this is the start address of the span corresponding to this
   // sampled allocation. This may be nullptr for cases where it is not useful
   // for residency analysis such as for peakheapz.
   void* span_start_address = nullptr;
 
-  // An integer representing the guarded status of the allocation.
-  // The values are from the enum GuardedStatus in ../malloc_extension.h.
-  int guarded_status;
-
-  // How the memory was allocated (new/malloc/etc.)
-  Profile::Sample::AllocationType allocation_type;
-
   uintptr_t depth;  // Number of PC values stored in array below
   // Place stack as last member because it might not all be accessed.
   void* stack[kMaxStackDepth];

tcmalloc/stack_trace_table.cc

@@ -86,8 +86,7 @@ void StackTraceTable::AddTrace(double sample_weight, const StackTrace& t) {
   s->sample.allocation_time = t.allocation_time;
 
   s->sample.span_start_address = t.span_start_address;
-  s->sample.guarded_status =
-      static_cast<Profile::Sample::GuardedStatus>(t.guarded_status);
+  s->sample.guarded_status = t.guarded_status;
   s->sample.type = t.allocation_type;
 
   static_assert(kMaxStackDepth <= Profile::Sample::kMaxStackDepth,