[tests] Choose the right simulator RID on x64. (#24874)

Author: rolfbjarne

tests/common/shared-dotnet.mk

@@ -88,9 +88,17 @@ endif
 
 ifeq ($(RID),)
 ifeq ($(PLATFORM),iOS)
+ifeq ($(shell arch),arm64)
 RID=iossimulator-arm64
+else
+RID=iossimulator-x64
+endif
 else ifeq ($(PLATFORM),tvOS)
+ifeq ($(shell arch),arm64)
 RID=tvossimulator-arm64
+else
+RID=tvossimulator-x64
+endif
 else ifeq ($(PLATFORM),MacCatalyst)
 ifeq ($(CONFIG),Release)
 RID=maccatalyst-x64;maccatalyst-arm64