Add tests for explicit true values and conflicting values

Author: gargaroff

llvm/test/CodeGen/MIR/Generic/machine-function-optionally-computed-properties.mir

@@ -1,5 +1,9 @@
 # RUN: llc -run-pass none -o - %s | FileCheck %s
-# Test that we can disable certain properties that are normally computed
+# Test that we can disable certain properties that are normally computed. This
+# override is a soft-override (only allows overriding when it relaxes the
+# property). Therefore, a conflicting override (e.g. setting noPhis to true in
+# the presence of PHI nodes) should not result in an error, but instead should
+# use the computed property instead (noPhis = false in the mentioned example).
 
 ---
 # CHECK-LABEL: name: TestNoPhis
@@ -15,6 +19,28 @@ name:            TestNoPhisOverride
 noPhis: false
 ...
 ---
+# CHECK-LABEL: name: TestNoPhisOverrideTrue
+# CHECK: noPhis: true
+# CHECK: ...
+name:            TestNoPhisOverrideTrue
+noPhis: true
+...
+---
+# CHECK-LABEL: name: TestNoPhisOverrideConflict
+# CHECK: noPhis: false
+# CHECK: ...
+name:            TestNoPhisOverrideConflict
+noPhis: true
+tracksRegLiveness: true
+body: |
+  bb.0:
+    %0:_(s32) = IMPLICIT_DEF
+
+  bb.1:
+    %1:_(s32) = PHI %0, %bb.0, %0, %bb.1
+    G_BR %bb.1
+...
+---
 # CHECK-LABEL: name: TestIsSSA
 # CHECK: isSSA: true
 # CHECK: ...
@@ -28,6 +54,24 @@ name:            TestIsSSAOverride
 isSSA: false
 ...
 ---
+# CHECK-LABEL: name: TestIsSSAOverrideTrue
+# CHECK: isSSA: true
+# CHECK: ...
+name:            TestIsSSAOverrideTrue
+isSSA: true
+...
+---
+# CHECK-LABEL: name: TestIsSSAOverrideConflict
+# CHECK: isSSA: false
+# CHECK: ...
+name:            TestIsSSAOverrideConflict
+isSSA: true
+body: |
+  bb.0:
+    %0:_(s32) = IMPLICIT_DEF
+    %0:_(s32) = IMPLICIT_DEF
+...
+---
 # CHECK-LABEL: name: TestNoVRegs
 # CHECK: noVRegs: true
 # CHECK: ...
@@ -40,3 +84,20 @@ name:            TestNoVRegs
 name:            TestNoVRegsOverride
 noVRegs: false
 ...
+---
+# CHECK-LABEL: name: TestNoVRegsOverrideTrue
+# CHECK: noVRegs: true
+# CHECK: ...
+name:            TestNoVRegsOverrideTrue
+noVRegs: true
+...
+---
+# CHECK-LABEL: name: TestNoVRegsOverrideConflict
+# CHECK: noVRegs: false
+# CHECK: ...
+name:            TestNoVRegsOverrideConflict
+noVRegs: true
+body: |
+  bb.0:
+    %0:_(s32) = IMPLICIT_DEF
+...