Enabled precise collection

For testing

Author: Jebbs

src/gc/config.d

@@ -26,7 +26,7 @@ struct Config
 {
     bool disable;            // start disabled
     ubyte profile;           // enable profiling with summary when terminating program
-    string gc = "conservative"; // select gc implementation conservative|precise|manual
+    string gc = "precise"; // select gc implementation conservative|precise|manual
 
     size_t initReserve;      // initial reserve (MB)
     size_t minPoolSize = 1;  // initial and minimum pool size (MB)

src/gc/impl/conservative/gc.d

@@ -294,7 +294,7 @@ class ConservativeGC : GC
     import core.internal.spinlock;
     static gcLock = shared(AlignedSpinLock)(SpinLock.Contention.lengthy);
     static bool _inFinalizer;
-    static bool isPrecise=false;
+    __gshared bool isPrecise=false;
 
     // lock GC, throw InvalidMemoryOperationError on recursive locking during finalization
     static void lockNR() @nogc nothrow