Add psset: a set of pageslabs.

This introduces a new sort of edata_t; a pageslab, and a set to manage them.
This is part of a series of a commits to implement a hugepage allocator; the
pageset will be per-arena, and track small page allocations requests within a
larger extent allocated from a centralized hugepage allocator.

msvc/projects/vc2015/jemalloc/jemalloc.vcxproj

@@ -76,6 +76,7 @@
     <ClCompile Include="..\..\..\..\src\prof_log.c" />
     <ClCompile Include="..\..\..\..\src\prof_recent.c" />
     <ClCompile Include="..\..\..\..\src\prof_sys.c" />
+    <ClCompile Include="..\..\..\..\src\psset.c" />
     <ClCompile Include="..\..\..\..\src\rtree.c" />
     <ClCompile Include="..\..\..\..\src\safety_check.c" />
     <ClCompile Include="..\..\..\..\src\sc.c" />

msvc/projects/vc2015/jemalloc/jemalloc.vcxproj.filters

@@ -112,6 +112,9 @@
     <ClCompile Include="..\..\..\..\src\prof_sys.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\..\..\src\psset.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\..\..\src\rtree.c">
       <Filter>Source Files</Filter>
     </ClCompile>

msvc/projects/vc2017/jemalloc/jemalloc.vcxproj

@@ -76,6 +76,7 @@
     <ClCompile Include="..\..\..\..\src\prof_log.c" />
     <ClCompile Include="..\..\..\..\src\prof_recent.c" />
     <ClCompile Include="..\..\..\..\src\prof_sys.c" />
+    <ClCompile Include="..\..\..\..\src\psset.c" />
     <ClCompile Include="..\..\..\..\src\rtree.c" />
     <ClCompile Include="..\..\..\..\src\safety_check.c" />
     <ClCompile Include="..\..\..\..\src\sc.c" />

msvc/projects/vc2017/jemalloc/jemalloc.vcxproj.filters

@@ -112,6 +112,9 @@
     <ClCompile Include="..\..\..\..\src\prof_sys.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\..\..\src\psset.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\..\..\src\rtree.c">
       <Filter>Source Files</Filter>
     </ClCompile>