[compiler-rt] [scudo] limit VMA size for riscv64 for DefaultConfig (PR #76013)

[via llvm-commits]

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@@ -124,8 +124,14 @@ struct DefaultConfig {
   struct Primary {
     using SizeClassMap = DefaultSizeClassMap;
 #if SCUDO_CAN_USE_PRIMARY64
+#if SCUDO_RISCV64
+    // Support 39-bit VMA for riscv-64
+    static const uptr RegionSizeLog = 30U;
+    static const uptr GroupSizeLog = 19U;
+#else
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ChiaHungDuan wrote:

Fuchsia has the default `RegionSizeLog=30` and `RegionSizeLog=28` for RISCV. There're other differences in the config but I want to know if `30` is smaller enough for RISCV or we should consider `28` as well. BTW, I think this is only for running tests, right? 

https://github.com/llvm/llvm-project/pull/76013