Simplify `CapabilitySet` Diagnostic Printing (#4678)

Fixes: #4675
Fixes: #4683
Fixes: #4443
Fixes: #4585
Fixes: #4172

Made the following changes:
1. All capability diagnostic printing logic tries to simplify before printing. This means that we do not print atoms which imply another atom.
2. Do not print the `_` prefix part of atom names since it is misleading users on what they should use to solve a capability issue encountered. (`_Internal` `External` atom changes are not in this PR)
3. Bundle together printing of all sets which contain exactly the same atoms (excluding abstract atoms). This allows printing the following `vertex/fragment/hull/domain/... + glsl` instead of `vertex + glsl | fragment + glsl | hull + glsl | domain + glsl | ....`
4. Rework how entry-point errors are reported to users (example at bottom of PR comment)
5. Rework how atom-provenance data is collected to be leaner and more useful so we can rework the errors. There are 2 notable changes here:
    * We no longer store a list which describes where the first of an `CapabilityAtom` comes from. This heavily simplifies AST logic for the capability system. AST parsing of capabilities is much faster. The trade-off is faster AST parsing and correct AST node data for slower diagnostics if an error is found
    * atom-provenance data now stores a reference to an atom's use-site to provide information on **where** and **what** is wrong with user code versus only sharing **what** and not where. 

1 files changed, 18 insertions, 0 deletions

diff --git a/source/slang/slang-capability.h b/source/slang/slang-capability.h
index cbdf48ac6..299e956e4 100644
--- a/source/slang/slang-capability.h
+++ b/source/slang/slang-capability.h
@@ -51,6 +51,8 @@ namespace Slang
 struct CapabilityAtomSet : UIntSet
 {
     using UIntSet::UIntSet;
+
+    CapabilityAtomSet newSetWithoutImpliedAtoms() const;
 };
 
 struct CapabilityTargetSet;
@@ -300,6 +302,22 @@ public:
     /// Add spirv version capabilities from 'spirv CapabilityTargetSet' as glsl_spirv version capability in 'glsl CapabilityTargetSet'
     void addSpirvVersionFromOtherAsGlslSpirvVersion(CapabilitySet& other);
 
+    /// Gets the first valid compile-target found in the CapabilitySet
+    CapabilityAtom getCompileTarget()
+    {
+        if(isEmpty() || isInvalid())
+            return CapabilityAtom::Invalid;
+        return (*m_targetSets.begin()).first;
+    }
+
+    /// Gets the first valid stage found in the CapabilitySet
+    CapabilityAtom getTargetStage()
+    {
+        if(isEmpty() || isInvalid())
+            return CapabilityAtom::Invalid;
+        return (*(*m_targetSets.begin()).second.shaderStageSets.begin()).first;
+    }
+
 private:
     /// underlying data of CapabilitySet.
     CapabilityTargetSets m_targetSets{};