Map GLintptr IDL type to Swift Int32 (#42)

This fixes an issue with 
```swift
func vertexAttribPointer(
  index: GLuint, 
  size: GLint, 
  type: GLenum, 
  normalized: GLboolean, 
  stride: GLsizei,
  offset: GLintptr
)
``` 
passing `offset` value of `BigInt` type to the JS function due to `public typealias GLintptr = Int64`, which led to `can't cast BigInt to number` runtime errors.

Either WebGL spec is wrong, or browsers implement it incorrectly. Rust folks had a similar issue and they went with `i32`, see wasm-bindgen/wasm-bindgen#800.

Author: MaxDesiatov

Sources/WebAPIKit/Generated.swift

@@ -21238,7 +21238,6 @@ public typealias GLbyte = Int8
 public typealias GLshort = Int16
 public typealias GLint = Int32
 public typealias GLsizei = Int32
-public typealias GLintptr = Int64
 public typealias GLsizeiptr = Int64
 public typealias GLubyte = UInt8
 public typealias GLushort = UInt16

Sources/WebAPIKit/Support.swift

@@ -1,5 +1,5 @@
-import JavaScriptKit
 @_exported import ECMAScript
+import JavaScriptKit
 
 /* TODO: fix this */
 public typealias __UNSUPPORTED_BIGINT__ = JSValue
@@ -22,3 +22,4 @@ public typealias HTMLOrSVGImageElement = HTMLImageElement
 public typealias HTMLOrSVGScriptElement = HTMLScriptElement
 public typealias BodyInit = XMLHttpRequestBodyInit
 public typealias CustomElementConstructor = JSFunction
+public typealias GLintptr = Int32

Sources/WebIDLToSwift/MergeDeclarations.swift

@@ -7,6 +7,9 @@ enum DeclarationMerger {
         "CustomElementConstructor",
         "ArrayBufferView",
         "RotationMatrixType",
+        // Mapped to `Int32` manually. This can't be represented as `Int64` due to `BigInt` representation on JS side,
+        // but as a pointer it can't be represented as floating point number either.
+        "GLintptr",
     ]
     static let validExposures: Set<String> = ["Window"]
 

Sources/WebIDLToSwift/WebIDL+SwiftRepresentation.swift

@@ -541,6 +541,7 @@ extension IDLType: SwiftRepresentable {
         "byte": "Int8",
         "short": "Int16",
         "long": "Int32",
+        // FIXME: this maps to BigInt when bridged to JS, which most probably leads to issues.
         "long long": "Int64",
         "Function": "JSFunction",
         "bigint": "__UNSUPPORTED_BIGINT__",