[SelectOptimize] Update Missing PSI Error Message, Add Test (#193034)

Update the error message to omit a period/start with a lowercase letter
per the coding standards. Also add a test as suggested in post-commit
feedback on #192871.

---------

Co-authored-by: Matt Arsenault <arsenm2@gmail.com>

Author: boomanaiden154

llvm/lib/CodeGen/SelectOptimize.cpp

@@ -370,8 +370,8 @@ PreservedAnalyses SelectOptimizeImpl::run(Function &F,
   PSI = FAM.getResult<ModuleAnalysisManagerFunctionProxy>(F)
             .getCachedResult<ProfileSummaryAnalysis>(*F.getParent());
   if (!PSI)
-    reportFatalUsageError("This pass requires the profile-summary module "
-                          "analysis to be available.");
+    reportFatalUsageError("this pass requires the profile-summary module "
+                          "analysis to be available");
   BFI = &FAM.getResult<BlockFrequencyAnalysis>(F);
 
   // When optimizing for size, selects are preferable over branches.

llvm/test/CodeGen/X86/select-optimize-psi.ll

@@ -0,0 +1,10 @@
+; RUN: not opt -mtriple=x86_64-unknown-unknown -passes='select-optimize' -disable-output < %s 2>&1 | FileCheck %s
+
+;; Check that if we try to run select-optimize without requiring PSI,
+;; we get an appropriate usage error rather than an assertion or crash.
+
+; CHECK: LLVM ERROR: this pass requires the profile-summary module analysis to be available
+
+define void @test() {
+  ret void
+}