Keep "srcs", "hdrs" and "textual_hdrs" separate.

Each can has slightly different semantics for the IDE, and it is better to use
the information on which files belong to which group from BUILD file rather than use heuristics like file extension to determine it.

The contents of "textual_hdrs" are added by the prefetcher.

RELNOTES: None.
PiperOrigin-RevId: 157256048

src/main/protobuf/intellij_ide_info.proto

@@ -62,6 +62,8 @@ message CIdeInfo {
   repeated string target_copt = 7;
   repeated string target_define = 8;
   repeated string target_include = 9;
+  repeated ArtifactLocation header = 10;
+  repeated ArtifactLocation textual_header = 11;
 }
 
 message AndroidIdeInfo {

tools/ide/intellij_info_impl.bzl

@@ -268,7 +268,8 @@ def build_c_ide_info(target, ctx):
     return (None, set())
 
   sources = artifacts_from_target_list_attr(ctx, "srcs")
-  sources.extend(artifacts_from_target_list_attr(ctx, "hdrs"))
+  headers = artifacts_from_target_list_attr(ctx, "hdrs")
+  textual_headers = artifacts_from_target_list_attr(ctx, "textual_hdrs")
 
   target_includes = []
   if hasattr(ctx.rule.attr, "includes"):
@@ -284,6 +285,8 @@ def build_c_ide_info(target, ctx):
 
   c_ide_info = struct_omit_none(
       source = sources,
+      header = headers,
+      textual_header = textual_headers,
       target_include = target_includes,
       target_define = target_defines,
       target_copt = target_copts,