[sparkplug] Implement OS::GetFreeMemoryRangesWithin() for Windows

Search for free memory ranges within the +/- 2GB boundary to the
embedded builtins. So that code range can be allocated close to the
binary to enable short builtin calls when pointer compression is
disabled.

Bug: v8:12045, v8:11527
Change-Id: I4698625882c3c7c39aff73b0bc874ddcfc990881
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3212466
Commit-Queue: Hao A Xu <hao.a.xu@intel.com>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77465}

src/base/platform/platform-win32.cc

@@ -1443,7 +1443,39 @@ void OS::AdjustSchedulingParams() {}
 std::vector<OS::MemoryRange> OS::GetFreeMemoryRangesWithin(
     OS::Address boundary_start, OS::Address boundary_end, size_t minimum_size,
     size_t alignment) {
-  return {};
+  std::vector<OS::MemoryRange> result = {};
+
+  // Search for the virtual memory (vm) ranges within the boundary.
+  // If a range is free and larger than {minimum_size}, then push it to the
+  // returned vector.
+  uintptr_t vm_start = RoundUp(boundary_start, alignment);
+  uintptr_t vm_end = 0;
+  MEMORY_BASIC_INFORMATION mi;
+  // This loop will terminate once the scanning reaches the higher address
+  // to the end of boundary or the function VirtualQuery fails.
+  while (vm_start < boundary_end &&
+         VirtualQuery(reinterpret_cast<LPCVOID>(vm_start), &mi, sizeof(mi)) !=
+             0) {
+    vm_start = reinterpret_cast<uintptr_t>(mi.BaseAddress);
+    vm_end = vm_start + mi.RegionSize;
+    if (mi.State == MEM_FREE) {
+      // The available area is the overlap of the virtual memory range and
+      // boundary. Push the overlapped memory range to the vector if there is
+      // enough space.
+      const uintptr_t overlap_start =
+          RoundUp(std::max(vm_start, boundary_start), alignment);
+      const uintptr_t overlap_end =
+          RoundDown(std::min(vm_end, boundary_end), alignment);
+      if (overlap_start < overlap_end &&
+          overlap_end - overlap_start >= minimum_size) {
+        result.push_back({overlap_start, overlap_end});
+      }
+    }
+    // Continue to visit the next virtual memory range.
+    vm_start = vm_end;
+  }
+
+  return result;
 }
 
 // static