We need this to ensure musl ppc targets use 64-bit long double, as our libgcc
ships without the 128-bit long double runtime funcs enabled for musl and even
if it did, the resulting binary would be incorrect.

--- a/lib/Basic/Targets/PPC.h
+++ b/lib/Basic/Targets/PPC.h
@@ -342,6 +342,15 @@ public:
       break;
     }
 
+    switch (getTriple().getEnvironment()) {
+    case llvm::Triple::Musl:
+      LongDoubleWidth = LongDoubleAlign = 64;
+      LongDoubleFormat = &llvm::APFloat::IEEEdouble();
+      break;
+    default:
+      break;
+    }
+
     // PPC32 supports atomics up to 4 bytes.
     MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 32;
   }
@@ -378,6 +387,15 @@ public:
       break;
     }
 
+    switch (getTriple().getEnvironment()) {
+    case llvm::Triple::Musl:
+      LongDoubleWidth = LongDoubleAlign = 64;
+      LongDoubleFormat = &llvm::APFloat::IEEEdouble();
+      break;
+    default:
+      break;
+    }
+
     // PPC64 supports atomics up to 8 bytes.
     MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 64;
   }