[Test] Improved some FileCheck variable names.

Author: nate-chandler

test/SILOptimizer/inline_lifetime.sil

@@ -429,11 +429,11 @@ bb2(%12 : @owned $Error):
 // CHECK-LABEL: sil [ossa] @callee_guaranteed_callee_error_guaranteed : $@convention(thin) (@guaranteed C) -> @error Error {
 // CHECK:       {{bb[^,]+}}([[INSTANCE:%[^,]+]] : @guaranteed $C):
 // CHECK:         [[LIFETIME:%[^,]+]] = begin_borrow [lexical] [[INSTANCE]]
-// CHECK:         cond_br undef, [[BASIC_BLOCK1:bb[^,]+]], [[BASIC_BLOCK2:bb[0-9]+]]
-// CHECK:       [[BASIC_BLOCK1]]:
+// CHECK:         cond_br undef, [[THROW_BLOCK:bb[^,]+]], [[REGULAR_BLOCK:bb[0-9]+]]
+// CHECK:       [[THROW_BLOCK]]:
 // CHECK:         end_borrow [[LIFETIME]]
 // CHECK:         throw undef
-// CHECK:       [[BASIC_BLOCK2]]:
+// CHECK:       [[REGULAR_BLOCK]]:
 // CHECK:         [[ORIGINAL_RETVAL:%[^,]+]] = tuple ()
 // CHECK:         end_borrow [[LIFETIME]]
 // CHECK:         [[RETVAL:%[^,]+]] = tuple ()