Dart SDK Spelling b, c, and d.

runtime/platform/globals.h

Index: runtime/platform/globals.h
diff --git a/runtime/platform/globals.h b/runtime/platform/globals.h
index ff171ac22258608d2817d656d5ee9efee230a43b..f56c0205e437a79a5eb5d88d8a818c02fc001b77 100644
--- a/runtime/platform/globals.h
+++ b/runtime/platform/globals.h
@@ -288,7 +288,7 @@ typedef simd128_value_t fpu_register_t;
 #define DART_UNUSED
 #endif
 
-// DART_NORETURN indicates to the compiler that a function doees not return.
+// DART_NORETURN indicates to the compiler that a function does not return.
 // It should be used on functions that unconditionally call functions like
 // exit(), which end the program. We use it to avoid compiler warnings in
 // callers of DART_NORETURN functions.
@@ -579,7 +579,7 @@ static inline void USE(T) {}
 // When you use implicit_cast, the compiler checks that the cast is safe.
 // Such explicit implicit_casts are necessary in surprisingly many
 // situations where C++ demands an exact type match instead of an
-// argument type convertable to a target type.
+// argument type convertible to a target type.
 //
 // The From type can be inferred, so the preferred syntax for using
 // implicit_cast is the same as for static_cast etc.: