Add precedence to contract members and top-level definitions

This fixes some ambiguities especially with built-ins.

crates/solidity/inputs/language/bindings/rules.msgb

@@ -93,6 +93,8 @@ inherit .star_extension
     )]
 ]] {
   edge @source_unit.lexical_scope -> @unit_member.def
+  attr (@source_unit.lexical_scope -> @unit_member.def) precedence = 1
+
   edge @source_unit.defs -> @unit_member.def
 
   ; In the general case, the lexical scope of the definition connects directly
@@ -342,6 +344,7 @@ inherit .star_extension
   attr (@contract.def) extension_scope = @contract.extensions
 
   edge @contract.lexical_scope -> @contract.instance
+  attr (@contract.lexical_scope -> @contract.instance) precedence = 1
 
   ; Instance scope can also see members and our namespace definitions
   edge @contract.instance -> @contract.members

crates/solidity/testing/snapshots/bindings_output/built_ins/shadowing/generated/0.4.11-failure.txt

@@ -4,9 +4,11 @@ Parse errors:
 Error: Expected ContractKeyword or ImportKeyword or InterfaceKeyword or LibraryKeyword or PragmaKeyword.
     ╭─[input.sol:14:1]
     │
- 14 │ function sha256() {}
-    │ ──────────┬──────────  
-    │           ╰──────────── Error occurred here.
+ 14 │ ╭─▶ function sha256() {}
+    ┆ ┆   
+ 18 │ ├─▶ }
+    │ │       
+    │ ╰─────── Error occurred here.
 ────╯
 References and definitions: 
     ╭─[input.sol:1:1]
@@ -29,10 +31,10 @@ References and definitions:
     │           ╰──── ref: 4
   7 │         tx;
     │         ─┬  
-    │          ╰── refs: 2, built-in
+    │          ╰── ref: 2
   8 │         sha256();
     │         ───┬──  
-    │            ╰──── refs: 5, built-in
+    │            ╰──── ref: 5
     │ 
  11 │     function sha256() public {}
     │              ───┬──  

crates/solidity/testing/snapshots/bindings_output/built_ins/shadowing/generated/0.6.0-failure.txt

@@ -4,9 +4,11 @@ Parse errors:
 Error: Expected ContractKeyword or EnumKeyword or ImportKeyword or InterfaceKeyword or LibraryKeyword or PragmaKeyword or StructKeyword.
     ╭─[input.sol:14:1]
     │
- 14 │ function sha256() {}
-    │ ──────────┬──────────  
-    │           ╰──────────── Error occurred here.
+ 14 │ ╭─▶ function sha256() {}
+    ┆ ┆   
+ 18 │ ├─▶ }
+    │ │       
+    │ ╰─────── Error occurred here.
 ────╯
 References and definitions: 
     ╭─[input.sol:1:1]
@@ -29,10 +31,10 @@ References and definitions:
     │           ╰──── ref: 4
   7 │         tx;
     │         ─┬  
-    │          ╰── refs: 2, built-in
+    │          ╰── ref: 2
   8 │         sha256();
     │         ───┬──  
-    │            ╰──── refs: 5, built-in
+    │            ╰──── ref: 5
     │ 
  11 │     function sha256() public {}
     │              ───┬──  

crates/solidity/testing/snapshots/bindings_output/built_ins/shadowing/generated/0.7.1-success.txt

@@ -21,10 +21,10 @@ References and definitions:
     │           ╰──── ref: 4
   7 │         tx;
     │         ─┬  
-    │          ╰── refs: 2, built-in
+    │          ╰── ref: 2
   8 │         sha256();
     │         ───┬──  
-    │            ╰──── refs: 6, 5, built-in
+    │            ╰──── ref: 5
     │ 
  11 │     function sha256() public {}
     │              ───┬──  
@@ -33,4 +33,11 @@ References and definitions:
  14 │ function sha256() {}
     │          ───┬──  
     │             ╰──── def: 6
+    │ 
+ 16 │ function top_level() {
+    │          ────┬────  
+    │              ╰────── def: 7
+ 17 │     sha256();
+    │     ───┬──  
+    │        ╰──── ref: 6
 ────╯

crates/solidity/testing/snapshots/bindings_output/built_ins/shadowing/input.sol

@@ -12,3 +12,7 @@ contract Test {
 }
 
 function sha256() {}
+
+function top_level() {
+    sha256();
+}

crates/solidity/testing/snapshots/bindings_output/scoping/shadowing/generated/0.4.11-failure.txt

@@ -0,0 +1,13 @@
+# This file is generated automatically by infrastructure scripts. Please don't edit by hand.
+
+Parse errors:
+Error: Expected ContractKeyword or ImportKeyword or InterfaceKeyword or LibraryKeyword or PragmaKeyword.
+    ╭─[input.sol:1:1]
+    │
+  1 │ ╭─▶ function foo() {}
+    ┆ ┆   
+ 18 │ ├─▶ }
+    │ │       
+    │ ╰─────── Error occurred here.
+────╯
+References and definitions: 

crates/solidity/testing/snapshots/bindings_output/scoping/shadowing/generated/0.6.0-failure.txt

@@ -0,0 +1,13 @@
+# This file is generated automatically by infrastructure scripts. Please don't edit by hand.
+
+Parse errors:
+Error: Expected ContractKeyword or EnumKeyword or ImportKeyword or InterfaceKeyword or LibraryKeyword or PragmaKeyword or StructKeyword.
+    ╭─[input.sol:1:1]
+    │
+  1 │ ╭─▶ function foo() {}
+    ┆ ┆   
+ 18 │ ├─▶ }
+    │ │       
+    │ ╰─────── Error occurred here.
+────╯
+References and definitions: 

crates/solidity/testing/snapshots/bindings_output/scoping/shadowing/generated/0.7.1-success.txt

@@ -0,0 +1,47 @@
+# This file is generated automatically by infrastructure scripts. Please don't edit by hand.
+
+References and definitions: 
+    ╭─[input.sol:1:1]
+    │
+  1 │ function foo() {}
+    │          ─┬─  
+    │           ╰─── def: 1
+  2 │ function bar() {}
+    │          ─┬─  
+    │           ╰─── def: 2
+    │ 
+  4 │ contract Base {
+    │          ──┬─  
+    │            ╰─── def: 3
+  5 │     function bar() public {}
+    │              ─┬─  
+    │               ╰─── def: 4
+    │ 
+  8 │ contract Test is Base {
+    │          ──┬─    ──┬─  
+    │            ╰─────────── def: 5
+    │                    │   
+    │                    ╰─── ref: 3
+  9 │     int x;
+    │         ┬  
+    │         ╰── def: 6
+    │ 
+ 11 │     function test(int x) public {
+    │              ──┬─     ┬  
+    │                ╰───────── def: 7
+    │                       │  
+    │                       ╰── def: 8
+ 12 │         foo();
+    │         ─┬─  
+    │          ╰─── ref: 9
+ 13 │         bar();
+    │         ─┬─  
+    │          ╰─── ref: 4
+ 14 │         x;
+    │         ┬  
+    │         ╰── ref: 8
+    │ 
+ 17 │     function foo() internal {}
+    │              ─┬─  
+    │               ╰─── def: 9
+────╯

crates/solidity/testing/snapshots/bindings_output/scoping/shadowing/input.sol

@@ -0,0 +1,18 @@
+function foo() {}
+function bar() {}
+
+contract Base {
+    function bar() public {}
+}
+
+contract Test is Base {
+    int x;
+
+    function test(int x) public {
+        foo();
+        bar();
+        x;
+    }
+
+    function foo() internal {}
+}