fix CI failure, revert changes to warn_impcast_matrix_scalar. the VectorConversion group is more invasive than expected

Author: farzonl

clang/include/clang/Basic/DiagnosticGroups.td

@@ -1337,7 +1337,7 @@ def : DiagGroup<"int-conversions",
 def : DiagGroup<"vector-conversions",
                 [VectorConversion]>; // -Wvector-conversions = -Wvector-conversion
 def : DiagGroup<"matrix-conversions",
-                [MatrixConversion]>; // -Wvector-conversions = -Wmatrix-conversion
+                [MatrixConversion]>; // -Wmatrix-conversions = -Wmatrix-conversion
 def : DiagGroup<"unused-local-typedefs", [UnusedLocalTypedef]>;
                 // -Wunused-local-typedefs = -Wunused-local-typedef
 

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -4361,7 +4361,7 @@ def warn_impcast_matrix_scalar : Warning<
   InGroup<MatrixConversion>, DefaultIgnore;
 def warn_impcast_vector_scalar : Warning<
   "implicit conversion turns vector to scalar: %0 to %1">,
-  InGroup<VectorConversion>, DefaultIgnore;
+  InGroup<Conversion>, DefaultIgnore;
 def warn_impcast_complex_scalar : Warning<
   "implicit conversion discards imaginary component: %0 to %1">,
   InGroup<Conversion>, DefaultIgnore;

clang/test/Driver/autocomplete.c

@@ -117,6 +117,8 @@
 // WARNING-NEXT: -Wmany-braces-around-scalar-init
 // WARNING-NEXT: -Wmath-errno-enabled-with-veclib
 // WARNING-NEXT: -Wmathematical-notation-identifier-extension
+// WARNING-NEXT: -Wmatrix-conversion
+// WARNING-NEXT: -Wmatrix-conversions
 // WARNING-NEXT: -Wmax-tokens
 // WARNING-NEXT: -Wmax-unsigned-zero
 // RUN: %clang --autocomplete=-Wno-invalid-pp- | FileCheck %s -check-prefix=NOWARNING