[NFC][compiler-rt][hwasan] Move shadow bound variables to hwasan.cpp

[leonardchan]

Summary

This way, other platforms can define these values.

compiler-rt/lib/hwasan/hwasan.cpp

 }
 
 int hwasan_inited = 0;
 int hwasan_instrumentation_inited = 0;
 bool hwasan_init_is_running;
 
 int hwasan_report_count = 0;
 
+uptr kLowShadowStart;
+uptr kLowShadowEnd;
+uptr kHighShadowStart;
+uptr kHighShadowEnd;
+
 void Flags::SetDefaults() {
 #define HWASAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
 #include "hwasan_flags.inc"
 #undef HWASAN_FLAG
 }
 
 static void RegisterHwasanFlags(FlagParser *parser, Flags *f) {
 #define HWASAN_FLAG(Type, Name, DefaultValue, Description) \

compiler-rt/lib/hwasan/hwasan_linux.cpp

 
 static void ProtectGap(uptr addr, uptr size) {
   __sanitizer::ProtectGap(addr, size, kZeroBaseShadowStart,
                           kZeroBaseMaxShadowStart);
 }
 
 uptr kLowMemStart;
 uptr kLowMemEnd;
-uptr kLowShadowEnd;
-uptr kLowShadowStart;
-uptr kHighShadowStart;
-uptr kHighShadowEnd;
 uptr kHighMemStart;
 uptr kHighMemEnd;
 
 uptr kAliasRegionStart;  // Always 0 when aliases aren't used.
 
 static void PrintRange(uptr start, uptr end, const char *name) {
   Printf("|| [%p, %p] || %.*s ||\n", (void *)start, (void *)end, 10, name);
 }