Use the more informative generic type inference failure error on method calls on raw pointers

compiler/rustc_error_codes/src/error_codes/E0699.md

@@ -1,8 +1,10 @@
+#### Note: this error code is no longer emitted by the compiler.
+
 A method was called on a raw pointer whose inner type wasn't completely known.
 
 Erroneous code example:
 
-```compile_fail,edition2018,E0699
+```compile_fail,edition2018
 # #![deny(warnings)]
 # fn main() {
 let foo = &1;

compiler/rustc_error_codes/src/lib.rs

@@ -441,7 +441,7 @@ E0695: 0695,
 E0696: 0696,
 E0697: 0697,
 E0698: 0698,
-E0699: 0699,
+E0699: 0699, // REMOVED: merged into generic inference var error
 E0700: 0700,
 E0701: 0701,
 E0703: 0703,