Improve linking-related error messages (#3353)

Include more contextual information about why the link failed related to
why the types didn't match.

Closes #3172

tests/misc_testsuite/linking-errors.wast

@@ -0,0 +1,47 @@
+(module $m
+  (global (export "g i32") i32 (i32.const 0))
+  (global (export "g mut i32") (mut i32)  (i32.const 0))
+
+  (table (export "t funcref") 0 funcref)
+  (memory (export "mem") 0)
+
+  (func (export "f"))
+  (func (export "f p1r2") (param f32) (result i32 i64) unreachable)
+)
+
+;; make sure the name of the import is in the message
+(assert_unlinkable
+  (module (import "m" "g i32" (global i64)))
+  "incompatible import type for `m::g i32`")
+
+;; errors on globals
+(assert_unlinkable
+  (module (import "m" "g i32" (global i64)))
+  "expected global of type `i64`, found global of type `i32`")
+
+(assert_unlinkable
+  (module (import "m" "g i32" (global (mut i32))))
+  "expected mutable global, found immutable global")
+
+(assert_unlinkable
+  (module (import "m" "g mut i32" (global i32)))
+  "expected immutable global, found mutable global")
+
+;; errors on tables
+(assert_unlinkable
+  (module (import "m" "t funcref" (table 1 funcref)))
+  "expected table limits (min: 1, max: none) doesn't match provided table limits (min: 0, max: none)")
+
+;; errors on memories
+(assert_unlinkable
+  (module (import "m" "mem" (memory 1)))
+  "expected memory limits (min: 1, max: none) doesn't match provided memory limits (min: 0, max: none)")
+
+;; errors on functions
+(assert_unlinkable
+  (module (import "m" "f" (func (param i32))))
+  "expected func of type `(i32) -> ()`, found func of type `() -> ()`")
+
+(assert_unlinkable
+  (module (import "m" "f p1r2" (func (param i32 i32) (result f64))))
+  "expected func of type `(i32, i32) -> (f64)`, found func of type `(f32) -> (i32, i64)`")