[nolibc] Move GetPageSize to the individual platforms.

GetPageSize wraps sysconf(_SC_PAGESIZE) on POSIX platforms, but
sysconf resides in libc.  To make this libc-independent on Linux,
move the wrapper to sanitizer_mac.cc and return the Linux-specific
constant EXEC_PAGESIZE in the sanitizer_linux.cc implementation.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@182303 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/sanitizer_common/sanitizer_linux.cc b/lib/sanitizer_common/sanitizer_linux.cc
index 778a31e..c326750 100644
--- a/lib/sanitizer_common/sanitizer_linux.cc
+++ b/lib/sanitizer_common/sanitizer_linux.cc
@@ -613,6 +613,10 @@
   return true;
 }
 
+uptr GetPageSize() {
+  return EXEC_PAGESIZE;
+}
+
 // Match full names of the form /path/to/base_name{-,.}*
 bool LibraryNameIs(const char *full_name, const char *base_name) {
   const char *name = full_name;
diff --git a/lib/sanitizer_common/sanitizer_mac.cc b/lib/sanitizer_common/sanitizer_mac.cc
index 9d74a48..f97d1e3 100644
--- a/lib/sanitizer_common/sanitizer_mac.cc
+++ b/lib/sanitizer_common/sanitizer_mac.cc
@@ -170,6 +170,10 @@
   // Nothing here for now.
 }
 
+uptr GetPageSize() {
+  return sysconf(_SC_PAGESIZE);
+}
+
 // ----------------- sanitizer_procmaps.h
 
 MemoryMappingLayout::MemoryMappingLayout(bool cache_enabled) {
diff --git a/lib/sanitizer_common/sanitizer_posix.cc b/lib/sanitizer_common/sanitizer_posix.cc
index 72dde4c..86e22db 100644
--- a/lib/sanitizer_common/sanitizer_posix.cc
+++ b/lib/sanitizer_common/sanitizer_posix.cc
@@ -35,10 +35,6 @@
 namespace __sanitizer {
 
 // ------------- sanitizer_common.h
-uptr GetPageSize() {
-  return sysconf(_SC_PAGESIZE);
-}
-
 uptr GetMmapGranularity() {
   return GetPageSize();
 }