[TableGen][RISCV] Strip experimental- prefix in profile names in SupportedExperimentalProfiles

This matches what we do for extensions, and saves us having to do it in
RISCVISAInfo.

This is a minor tweak to what I added in #91993.

Author: asb

llvm/test/TableGen/riscv-target-def.td

@@ -147,7 +147,7 @@ def ROCKET : RISCVTuneProcessorModel<"rocket",
 // CHECK-NEXT: };
 
 // CHECK:      static constexpr RISCVProfile SupportedExperimentalProfiles[] = {
-// CHECK-NEXT:     {"experimental-rvi99u64","rv64i2p1"},
+// CHECK-NEXT:     {"rvi99u64","rv64i2p1"},
 // CHECK-NEXT: };
 
 // CHECK:      #endif // GET_SUPPORTED_PROFILES

llvm/utils/TableGen/RISCVTargetDefEmitter.cpp

@@ -134,7 +134,9 @@ static void printProfileTable(raw_ostream &OS,
     if (Rec->getValueAsBit("Experimental") != Experimental)
       continue;
 
-    OS.indent(4) << "{\"" << Rec->getValueAsString("Name") << "\",\"";
+    StringRef Name = Rec->getValueAsString("Name");
+    Name.consume_front("experimental-");
+    OS.indent(4) << "{\"" << Name << "\",\"";
     printMArch(OS, Rec->getValueAsListOfDefs("Implies"));
     OS << "\"},\n";
   }