Rollup merge of #124797 - beetrees:primitive-float, r=davidtwco

Refactor float `Primitive`s to a separate `Float` type

Now there are 4 of them, it makes sense to refactor `F16`, `F32`, `F64` and `F128` out of `Primitive` and into a separate `Float` type (like integers already are). This allows patterns like `F16 | F32 | F64 | F128` to be simplified into `Float(_)`, and is consistent with `ty::FloatTy`.

As a side effect, this PR also makes the `Ty::primitive_size` method work with `f16` and `f128`.

Tracking issue: #116909

`@rustbot` label +F-f16_and_f128

src/type_of.rs

@@ -8,8 +8,8 @@
 use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 use rustc_target::abi::call::{CastTarget, FnAbi, Reg};
 use rustc_target::abi::{
-    self, Abi, Align, FieldsShape, Int, Integer, PointeeInfo, Pointer, Size, TyAbiInterface,
-    Variants, F128, F16, F32, F64,
+    self, Abi, Align, FieldsShape, Float, Int, Integer, PointeeInfo, Pointer, Size, TyAbiInterface,
+    Variants,
 };
 
 use crate::abi::{FnAbiGcc, FnAbiGccExt, GccType};
@@ -283,10 +283,7 @@ fn scalar_gcc_type_at<'gcc>(
         match scalar.primitive() {
             Int(i, true) => cx.type_from_integer(i),
             Int(i, false) => cx.type_from_unsigned_integer(i),
-            F16 => cx.type_f16(),
-            F32 => cx.type_f32(),
-            F64 => cx.type_f64(),
-            F128 => cx.type_f128(),
+            Float(f) => cx.type_from_float(f),
             Pointer(address_space) => {
                 // If we know the alignment, pick something better than i8.
                 let pointee = if let Some(pointee) = self.pointee_info_at(cx, offset) {