Fix Parser::break_up_float fractional part's span

Author: ShE3py

compiler/rustc_parse/src/parser/expr.rs

@@ -1103,7 +1103,7 @@ impl<'a> Parser<'a> {
                     let dot_span = span
                         .with_lo(span.lo + ident1_len)
                         .with_hi(span.lo + ident1_len + BytePos(1));
-                    let ident2_span = self.token.span.with_lo(span.lo + ident1_len + BytePos(1));
+                    let ident2_span = span.with_lo(span.lo + ident1_len + BytePos(1));
                     (ident1_span, dot_span, ident2_span)
                 } else {
                     (span, span, span)

tests/ui/feature-gates/feature-gate-offset-of-nested.stderr

@@ -11,19 +11,12 @@ LL |     offset_of!(Alpha, Two.0);
 error[E0658]: only a single ident or integer is stable as the field in offset_of
   --> $DIR/feature-gate-offset-of-nested.rs:24:33
    |
-LL |       offset_of!((u32, (S, T)), 1.1);
-   |  _____----------------------------^-
-   | |     |
-   | |     in this macro invocation
-LL | |     offset_of!(S, b.0);
-LL | |     offset_of!((S, ()), 0.c);
-LL | |     offset_of!(S, c.t);
-...  |
+LL |     offset_of!((u32, (S, T)), 1.1);
+   |                                 ^
    |
    = note: see issue #120140 <https://github.com/rust-lang/rust/issues/120140> for more information
    = help: add `#![feature(offset_of_nested)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-   = note: this error originates in the macro `offset_of` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0658]: only a single ident or integer is stable as the field in offset_of
   --> $DIR/feature-gate-offset-of-nested.rs:25:21

tests/ui/offset-of/offset-of-tuple.stderr

@@ -196,15 +196,8 @@ LL |     builtin # offset_of((u8, u8), 1_u8);
 error[E0609]: no field `2` on type `(u8, u16)`
   --> $DIR/offset-of-tuple.rs:31:47
    |
-LL |       offset_of!(((u8, u16), (u32, u16, u8)), 0.2);
-   |  _____------------------------------------------^-
-   | |     |
-   | |     in this macro invocation
-LL | |     offset_of!(((u8, u16), (u32, u16, u8)), 1.2);
-LL | |     offset_of!(((u8, u16), (u32, u16, u8)), 1.2.0);
-...  |
-   |
-   = note: this error originates in the macro `offset_of` (in Nightly builds, run with -Z macro-backtrace for more info)
+LL |     offset_of!(((u8, u16), (u32, u16, u8)), 0.2);
+   |                                               ^
 
 error[E0609]: no field `0` on type `u8`
   --> $DIR/offset-of-tuple.rs:33:49