[AArch64] Lower jump table cases threshold to 10

Previous stabs at this setting hypertuned it for SPEC2017, but Clang's
own compilation can benefit from a slightly lower threshold, yielding
0.3% improvement in compile time, while still maintaining a 0.1%
improvement in SPEC2017.

Most notable benefactors of this change are:
 - llvm::Instruction::getNumSuccessors (11 cases)
 - llvm::Instruction::getSuccessor (11 cases)

Author: guy-david

llvm/lib/Target/AArch64/AArch64Subtarget.cpp

@@ -73,7 +73,7 @@ static cl::opt<AArch64PAuth::AuthCheckMethod>
                                cl::values(AUTH_CHECK_METHOD_CL_VALUES_LR));
 
 static cl::opt<unsigned> AArch64MinimumJumpTableEntries(
-    "aarch64-min-jump-table-entries", cl::init(13), cl::Hidden,
+    "aarch64-min-jump-table-entries", cl::init(10), cl::Hidden,
     cl::desc("Set minimum number of entries to use a jump table on AArch64"));
 
 static cl::opt<unsigned> AArch64StreamingHazardSize(