Merge #1220

1220: Add macro pat parsing r=matklad a=edwin0cheng

This PR add support to parsing macro call in pattern , e.g :
```
let m!(x) = 0;
```

Co-authored-by: Edwin Cheng <[email protected]>

2 files changed, 39 insertions, 0 deletions

diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0129_marco_pat.rs b/crates/ra_syntax/tests/data/parser/inline/ok/0129_marco_pat.rs
new file mode 100644
index 000000000..811181d9b
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0129_marco_pat.rs
@@ -0,0 +1,3 @@
+fn main() {
+    let m!(x) = 0;
+}
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0129_marco_pat.txt b/crates/ra_syntax/tests/data/parser/inline/ok/0129_marco_pat.txt
new file mode 100644
index 000000000..50b4ab2e7
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0129_marco_pat.txt
@@ -0,0 +1,36 @@
+SOURCE_FILE@[0; 33)
+  FN_DEF@[0; 32)
+    FN_KW@[0; 2) "fn"
+    WHITESPACE@[2; 3) " "
+    NAME@[3; 7)
+      IDENT@[3; 7) "main"
+    PARAM_LIST@[7; 9)
+      L_PAREN@[7; 8) "("
+      R_PAREN@[8; 9) ")"
+    WHITESPACE@[9; 10) " "
+    BLOCK@[10; 32)
+      L_CURLY@[10; 11) "{"
+      WHITESPACE@[11; 16) "\n    "
+      LET_STMT@[16; 30)
+        LET_KW@[16; 19) "let"
+        WHITESPACE@[19; 20) " "
+        MACRO_CALL@[20; 25)
+          PATH_PAT@[20; 21)
+            PATH@[20; 21)
+              PATH_SEGMENT@[20; 21)
+                NAME_REF@[20; 21)
+                  IDENT@[20; 21) "m"
+          EXCL@[21; 22) "!"
+          TOKEN_TREE@[22; 25)
+            L_PAREN@[22; 23) "("
+            IDENT@[23; 24) "x"
+            R_PAREN@[24; 25) ")"
+        WHITESPACE@[25; 26) " "
+        EQ@[26; 27) "="
+        WHITESPACE@[27; 28) " "
+        LITERAL@[28; 29)
+          INT_NUMBER@[28; 29) "0"
+        SEMI@[29; 30) ";"
+      WHITESPACE@[30; 31) "\n"
+      R_CURLY@[31; 32) "}"
+  WHITESPACE@[32; 33) "\n"