[llvm-exegesis][unittests] Also disable SubprocessMemoryTest on SPARC (llvm#102755)

Three `llvm-exegesis` tests
```
  LLVM-Unit :: tools/llvm-exegesis/./LLVMExegesisTests/SubprocessMemoryTest/DefinitionFillsCompletely
  LLVM-Unit :: tools/llvm-exegesis/./LLVMExegesisTests/SubprocessMemoryTest/MultipleDefinitions
  LLVM-Unit :: tools/llvm-exegesis/./LLVMExegesisTests/SubprocessMemoryTest/OneDefinition
```
`FAIL` on Linux/sparc64 like
```
llvm/unittests/tools/llvm-exegesis/X86/SubprocessMemoryTest.cpp:68: Failure
Expected equality of these values:
  SharedMemoryMapping[I]
    Which is: '\0'
  ExpectedValue[I]
    Which is: '\xAA' (170)
```
It seems like this test only works on little-endian hosts: three
sub-tests are already disabled on powerpc and s390x (both big-endian),
and the fourth is additionally guarded against big-endian hosts (making
the other guards unnecessary).

However, since it's not been analyzed if this is really an endianess
issue, this patch disables the whole test on powerpc and s390x as before
adding sparc to the mix.

Tested on `sparc64-unknown-linux-gnu` and `x86_64-pc-linux-gnu`.

(cherry picked from commit a417083)

Author: rorth

llvm/unittests/tools/llvm-exegesis/X86/SubprocessMemoryTest.cpp

@@ -24,7 +24,8 @@
 namespace llvm {
 namespace exegesis {
 
-#if defined(__linux__) && !defined(__ANDROID__)
+#if defined(__linux__) && !defined(__ANDROID__) &&                             \
+    !(defined(__powerpc__) || defined(__s390x__) || defined(__sparc__))
 
 // This needs to be updated anytime a test is added or removed from the test
 // suite.
@@ -77,20 +78,12 @@ class SubprocessMemoryTest : public X86TestBase {
 // memory calls not working in some cases, so they have been disabled.
 // TODO(boomanaiden154): Investigate and fix this issue on PPC.
 
-#if defined(__powerpc__) || defined(__s390x__)
-TEST_F(SubprocessMemoryTest, DISABLED_OneDefinition) {
-#else
 TEST_F(SubprocessMemoryTest, OneDefinition) {
-#endif
   testCommon({{"test1", {APInt(8, 0xff), 4096, 0}}}, 0);
   checkSharedMemoryDefinition(getSharedMemoryName(0, 0), 4096, {0xff});
 }
 
-#if defined(__powerpc__) || defined(__s390x__)
-TEST_F(SubprocessMemoryTest, DISABLED_MultipleDefinitions) {
-#else
 TEST_F(SubprocessMemoryTest, MultipleDefinitions) {
-#endif
   testCommon({{"test1", {APInt(8, 0xaa), 4096, 0}},
               {"test2", {APInt(8, 0xbb), 4096, 1}},
               {"test3", {APInt(8, 0xcc), 4096, 2}}},
@@ -100,11 +93,7 @@ TEST_F(SubprocessMemoryTest, MultipleDefinitions) {
   checkSharedMemoryDefinition(getSharedMemoryName(1, 2), 4096, {0xcc});
 }
 
-#if defined(__powerpc__) || defined(__s390x__)
-TEST_F(SubprocessMemoryTest, DISABLED_DefinitionFillsCompletely) {
-#else
 TEST_F(SubprocessMemoryTest, DefinitionFillsCompletely) {
-#endif
   testCommon({{"test1", {APInt(8, 0xaa), 4096, 0}},
               {"test2", {APInt(16, 0xbbbb), 4096, 1}},
               {"test3", {APInt(24, 0xcccccc), 4096, 2}}},
@@ -118,7 +107,7 @@ TEST_F(SubprocessMemoryTest, DefinitionFillsCompletely) {
 }
 
 // The following test is only supported on little endian systems.
-#if defined(__powerpc__) || defined(__s390x__) || __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 TEST_F(SubprocessMemoryTest, DISABLED_DefinitionEndTruncation) {
 #else
 TEST_F(SubprocessMemoryTest, DefinitionEndTruncation) {
@@ -150,7 +139,7 @@ TEST_F(SubprocessMemoryTest, DefinitionEndTruncation) {
   checkSharedMemoryDefinition(getSharedMemoryName(3, 0), 4096, Test1Expected);
 }
 
-#endif // defined(__linux__) && !defined(__ANDROID__)
+#endif // __linux__ && !__ANDROID__ && !(__powerpc__ || __s390x__ || __sparc__)
 
 } // namespace exegesis
 } // namespace llvm