Spellchecking some comments

This PR attempts to clean up some minor spelling mistakes in comments

compiler/rustc_codegen_gcc/src/builder.rs

@@ -508,7 +508,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
     }
 
     fn exactsdiv(&mut self, a: RValue<'gcc>, b: RValue<'gcc>) -> RValue<'gcc> {
-        // TODO(antoyo): posion if not exact.
+        // TODO(antoyo): poison if not exact.
         // FIXME(antoyo): rustc_codegen_ssa::mir::intrinsic uses different types for a and b but they
         // should be the same.
         let typ = a.get_type().to_signed(self);
@@ -1252,7 +1252,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
     }
 
     fn do_not_inline(&mut self, _llret: RValue<'gcc>) {
-        // FIMXE(bjorn3): implement
+        // FIXME(bjorn3): implement
     }
 
     fn set_span(&mut self, _span: Span) {}

compiler/rustc_codegen_gcc/src/context.rs

@@ -110,7 +110,7 @@ pub struct CodegenCx<'gcc, 'tcx> {
     /// NOTE: a hack is used because the rustc API is not suitable to libgccjit and as such,
     /// `const_undef()` returns struct as pointer so that they can later be assigned a value.
     /// As such, this set remembers which of these pointers were returned by this function so that
-    /// they can be deferenced later.
+    /// they can be dereferenced later.
     /// FIXME(antoyo): fix the rustc API to avoid having this hack.
     pub structs_as_pointer: RefCell<FxHashSet<RValue<'gcc>>>,
 }

compiler/rustc_codegen_gcc/src/intrinsic/mod.rs

@@ -340,7 +340,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
     }
 
     fn assume(&mut self, value: Self::Value) {
-        // TODO(antoyo): switch to asumme when it exists.
+        // TODO(antoyo): switch to assume when it exists.
         // Or use something like this:
         // #define __assume(cond) do { if (!(cond)) __builtin_unreachable(); } while (0)
         self.expect(value, true);