target: drop ppc32 and prefer ppc

- original PR #7949 (incorrectly) patched a generated-file and changes
  have subsequently been lost/overwritten
- fix #7947 in a different way: drop `ppc32` because `ppc` already exists

lib/std/target.zig

@@ -1184,8 +1184,8 @@ pub const Target = struct {
                     .mips, .mipsel => &mips.cpu.mips32,
                     .mips64, .mips64el => &mips.cpu.mips64,
                     .msp430 => &msp430.cpu.generic,
-                    .powerpc => &powerpc.cpu.ppc32,
-                    .powerpcle => &powerpc.cpu.ppc32,
+                    .powerpc => &powerpc.cpu.ppc,
+                    .powerpcle => &powerpc.cpu.ppc,
                     .powerpc64 => &powerpc.cpu.ppc64,
                     .powerpc64le => &powerpc.cpu.ppc64le,
                     .amdgcn => &amdgpu.cpu.generic,

lib/std/target/powerpc.zig

@@ -751,13 +751,6 @@ pub const cpu = struct {
             .hard_float,
         }),
     };
-    pub const ppc32 = CpuModel{
-        .name = "ppc32",
-        .llvm_name = "ppc32",
-        .features = featureSet(&[_]Feature{
-            .hard_float,
-        }),
-    };
     pub const ppc64 = CpuModel{
         .name = "ppc64",
         .llvm_name = "ppc64",

tools/update_cpu_features.zig

@@ -663,6 +663,12 @@ const llvm_targets = [_]LlvmTarget{
         .zig_name = "powerpc",
         .llvm_name = "PowerPC",
         .td_name = "PPC.td",
+        .feature_overrides = &.{
+            .{
+                .llvm_name = "ppc32",
+                .omit = true,
+            },
+        },
     },
     .{
         .zig_name = "riscv",