UpdateTestChecks: squelch warning on SCEV output (#67443)

update_analyze_test_checks.py currently outputs a warning when updating
a script with the run line:

  $ opt -passes='print<scalar-evolution>'

saying that the script doesn't support its output, when it indeed does,
as evidenced by several tests in test/Analysis/ScalarEvolution generated
by this script. There is even a test for update_analyze_test_checks that
makes sure that SCEV output is supported. Hence, squelch the warning.

While at it, rename the update_analyze_test_checks test from basic.ll to
a more explicit scev.ll.

Author: artagnon

llvm/test/tools/UpdateTestChecks/update_analyze_test_checks/Inputs/basic.ll renamed to llvm/test/tools/UpdateTestChecks/update_analyze_test_checks/Inputs/scev.ll

@@ -1,6 +1,6 @@
 ## Basic test checking that update_analyze_test_checks.py works correctly
-# RUN: cp -f %S/Inputs/basic.ll %t.ll && %update_analyze_test_checks %t.ll
-# RUN: diff -u %t.ll %S/Inputs/basic.ll.expected
+# RUN: cp -f %S/Inputs/scev.ll %t.ll && %update_analyze_test_checks %t.ll
+# RUN: diff -u %t.ll %S/Inputs/scev.ll.expected
 ## Check that running the script again does not change the result:
 # RUN: %update_analyze_test_checks %t.ll
-# RUN: diff -u %t.ll %S/Inputs/basic.ll.expected
+# RUN: diff -u %t.ll %S/Inputs/scev.ll.expected

llvm/test/tools/UpdateTestChecks/update_analyze_test_checks/Inputs/basic.ll.expected renamed to llvm/test/tools/UpdateTestChecks/update_analyze_test_checks/Inputs/scev.ll.expected

@@ -767,7 +767,11 @@ def process_run_line(
             )
             if "analysis" in m.groupdict():
                 analysis = m.group("analysis")
-                if analysis.lower() != "cost model analysis":
+                supported_analyses = {
+                    "cost model analysis",
+                    "scalar evolution analysis",
+                }
+                if analysis.lower() not in supported_analyses:
                     warn("Unsupported analysis mode: %r!" % (analysis,))
             if func.startswith("stress"):
                 # We only use the last line of the function body for stress tests.