[PowerPC] Stop defining _ARCH_PWR6X on POWER7 and up

Summary:
The predefined macro `_ARCH_PWR6X` is associated with GCC's
`-mcpu=power6x` option, which enables generation of P6 "raw mode"
instructions such as `mftgpr`.

Later POWER processors build upon the "architected mode", not the raw
one. `_ARCH_PWR6X` should not be defined for these later processors.

Fixes PR#40236.

Reviewers: echristo, hfinkel, kbarton, nemanjai, wschmidt

Reviewed By: hfinkel

Subscribers: jsji, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58128

llvm-svn: 353975
diff --git a/clang/lib/Basic/Targets/PPC.h b/clang/lib/Basic/Targets/PPC.h
index b168439..ecfc1bc 100644
--- a/clang/lib/Basic/Targets/PPC.h
+++ b/clang/lib/Basic/Targets/PPC.h
@@ -131,19 +131,18 @@
                         ArchDefinePwr5 | ArchDefinePwr4 | ArchDefinePpcgr |
                         ArchDefinePpcsq)
               .Cases("power7", "pwr7",
-                    ArchDefinePwr7 | ArchDefinePwr6x | ArchDefinePwr6 |
-                        ArchDefinePwr5x | ArchDefinePwr5 | ArchDefinePwr4 |
-                        ArchDefinePpcgr | ArchDefinePpcsq)
+                     ArchDefinePwr7 | ArchDefinePwr6 | ArchDefinePwr5x |
+                         ArchDefinePwr5 | ArchDefinePwr4 | ArchDefinePpcgr |
+                         ArchDefinePpcsq)
               // powerpc64le automatically defaults to at least power8.
               .Cases("power8", "pwr8", "ppc64le",
-                    ArchDefinePwr8 | ArchDefinePwr7 | ArchDefinePwr6x |
-                        ArchDefinePwr6 | ArchDefinePwr5x | ArchDefinePwr5 |
-                        ArchDefinePwr4 | ArchDefinePpcgr | ArchDefinePpcsq)
+                     ArchDefinePwr8 | ArchDefinePwr7 | ArchDefinePwr6 |
+                         ArchDefinePwr5x | ArchDefinePwr5 | ArchDefinePwr4 |
+                         ArchDefinePpcgr | ArchDefinePpcsq)
               .Cases("power9", "pwr9",
-                    ArchDefinePwr9 | ArchDefinePwr8 | ArchDefinePwr7 |
-                        ArchDefinePwr6x | ArchDefinePwr6 | ArchDefinePwr5x |
-                        ArchDefinePwr5 | ArchDefinePwr4 | ArchDefinePpcgr |
-                        ArchDefinePpcsq)
+                     ArchDefinePwr9 | ArchDefinePwr8 | ArchDefinePwr7 |
+                         ArchDefinePwr6 | ArchDefinePwr5x | ArchDefinePwr5 |
+                         ArchDefinePwr4 | ArchDefinePpcgr | ArchDefinePpcsq)
               .Default(ArchDefineNone);
     }
     return CPUKnown;