rustc_target: ppc64 target string fixes for LLVM 20

LLVM continues to clean these up, and we continue to make this
consistent. This is similar to 9caced7,
e985396, and
a10e744.

`@rustbot` label: +llvm-main

Author: durin42

compiler/rustc_codegen_llvm/src/context.rs

@@ -159,6 +159,11 @@ pub(crate) unsafe fn create_module<'ll>(
             // See https://github.com/llvm/llvm-project/pull/112084
             target_data_layout = target_data_layout.replace("-i128:128", "");
         }
+        if sess.target.arch.starts_with("powerpc64") {
+            // LLVM 20 updates the powerpc64 layout to correctly align 128 bit integers to 128 bit.
+            // See https://github.com/llvm/llvm-project/pull/118004
+            target_data_layout = target_data_layout.replace("-i128:128", "");
+        }
     }
 
     // Ensure the data-layout values hardcoded remain the defaults.

compiler/rustc_target/src/spec/targets/powerpc64_ibm_aix.rs

@@ -19,7 +19,7 @@ pub(crate) fn target() -> Target {
             std: None, // ?
         },
         pointer_width: 64,
-        data_layout: "E-m:a-Fi64-i64:64-n32:64-S128-v256:256:256-v512:512:512".into(),
+        data_layout: "E-m:a-Fi64-i64:64-i128:128-n32:64-S128-v256:256:256-v512:512:512".into(),
         arch: "powerpc64".into(),
         options: base,
     }

compiler/rustc_target/src/spec/targets/powerpc64_unknown_linux_gnu.rs

@@ -17,7 +17,7 @@ pub(crate) fn target() -> Target {
             std: Some(true),
         },
         pointer_width: 64,
-        data_layout: "E-m:e-Fi64-i64:64-n32:64-S128-v256:256:256-v512:512:512".into(),
+        data_layout: "E-m:e-Fi64-i64:64-i128:128-n32:64-S128-v256:256:256-v512:512:512".into(),
         arch: "powerpc64".into(),
         options: TargetOptions { endian: Endian::Big, mcount: "_mcount".into(), ..base },
     }

compiler/rustc_target/src/spec/targets/powerpc64_wrs_vxworks.rs

@@ -17,7 +17,7 @@ pub(crate) fn target() -> Target {
             std: Some(true),
         },
         pointer_width: 64,
-        data_layout: "E-m:e-Fi64-i64:64-n32:64-S128-v256:256:256-v512:512:512".into(),
+        data_layout: "E-m:e-Fi64-i64:64-i128:128-n32:64-S128-v256:256:256-v512:512:512".into(),
         arch: "powerpc64".into(),
         options: TargetOptions { endian: Endian::Big, ..base },
     }

compiler/rustc_target/src/spec/targets/powerpc64le_unknown_linux_gnu.rs

@@ -16,7 +16,7 @@ pub(crate) fn target() -> Target {
             std: Some(true),
         },
         pointer_width: 64,
-        data_layout: "e-m:e-Fn32-i64:64-n32:64-S128-v256:256:256-v512:512:512".into(),
+        data_layout: "e-m:e-Fn32-i64:64-i128:128-n32:64-S128-v256:256:256-v512:512:512".into(),
         arch: "powerpc64".into(),
         options: TargetOptions { mcount: "_mcount".into(), ..base },
     }

compiler/rustc_target/src/spec/targets/powerpc64le_unknown_linux_musl.rs

@@ -16,7 +16,7 @@ pub(crate) fn target() -> Target {
             std: None, // ?
         },
         pointer_width: 64,
-        data_layout: "e-m:e-Fn32-i64:64-n32:64-S128-v256:256:256-v512:512:512".into(),
+        data_layout: "e-m:e-Fn32-i64:64-i128:128-n32:64-S128-v256:256:256-v512:512:512".into(),
         arch: "powerpc64".into(),
         options: TargetOptions { mcount: "_mcount".into(), ..base },
     }